Who knew that the biggest TV story of 2011 would be a sitcom cast change? The Charlie Sheen meltdown and subsequent public firing from the CBS hit Two And A Half Men, followed by the show’s successful  transition with new star Ashton Kutcher and Sheen’s comeback in the new comedy series Anger Management, grabbed the biggest headlines. But it was eventful year, featuring major shakeups in daytime and off-network syndication as well as ushering in new players in original programming and a comeback for comedy.

No other TV area saw more dramatic changes in 2011 than daytime. Soaps’ march toward extinction accelerated with the demise of ABC’s One Life To Live and All My Children. Two other staples of daytime TV, talk show queen Oprah Winfrey and another longtime host Regis Philbin, made their departures. Winfrey’s exit changed the landscape of daytime television, which she had dominated for a quarter of a century. With her gone, two big names threw their hats in the daytime talk show ring this year — former Today co-host-turned-CBS Evening News anchor Katie Couric, whose job change once again became a media circus, and Queen Latifah. Couric’s Disney-ABC talker launches next fall, Queen Latifah’s Sony TV-produced talk show is targeted for fall 2012.

Closing one chapter, Winfrey and the ABC soaps tried to open another, but the transition proved bumpy for all. On Jan. 1, 2011, Winfrey launched OWN: The Oprah Winfrey Network. A year and some $300 million in investment by Discovery Communications later, OWN is still struggling to find an audience and outperform the Discovery Health network it replaced. Heavily promoted entries like Mark Burnett’s reality series Your OWN Show, Oprah Presents Master Class and the Rosie O’Donnell talk show have disappointed, and the network has been mulling a more niche approach, catering to African American audiences. Winfrey will make another attempt to salvage her network with Oprah’s Next Chapter, a new weekly primetime show, which premieres on Jan. 1, OWN’s first anniversary.

There will be no next chapter for canceled ABC soaps All My Children and One Life To Live. After a five-month effort to secure financial backers and union agreements, Jeff Kwatinetz’s Prospect Park recently abandoned its plans to continue the daytime dramas online after licensing the shows from ABC in July.

While Prospect Park couldn’t find a business model that would sustain network quality series online, another company, Netflix, made a big bet this year that it can make it work. In the most significant challenge to traditional TV networks to date, the streaming giant last spring outbid the network with deepest pockets, HBO, for the David Fincher-Kevin Spacey drama House Of Cards in a deal that could be worth more than $100 million. Since then, despite the company’s stock price woes stemming from blunders in the core DVD rental/movie and TV shows streaming business like the ill-fated Qwikster spin-off and fee hike, Netflix has been aggressively building a slate of original series. In the past couple of months, it picked up Jenji Kohan’s comedy Orange Is The New Black, Eli Roth’s horror thriller Hemlock Grove and a new season of Arrested Development.

Along with Netflix, there were traditional TV networks that also made their first foray into original scripted series this year as the value of original programming continues to rise in a crowded TV universe. (Just look at the ratings declines for rerun-driven Nick at Nite.) It isn’t easy. CMT launched its first sitcom, Working Class, in January. After a lackluster run, the network switched directions, abandoning scripted series and betting on original movies and reality shows instead. Also this year, BBC America greenlighted its first original series — several unscripted shows and a scripted drama, Copper. And ReelzChannel became a somewhat accidental original programming player when it picked up controversial miniseries The Kennedys after it was dropped by History. The fledgling channel has since acquired original scripted and unscripted series and a potential awards franchise, Critics’ Choice TV Awards. On the broadcast side, ION entered the original series arena with new episodes of Canadian drama Flashpoint.

In addition to challenging the traditional networks in the original series arena, Netflix also revolutionized the off-network syndication business this year. For decades, TV studios have focused mainly on procedurals on the hourlong side, shunning serialized dramas because they have very little syndication value. Who can blame them when procedurals like NCIS: LA, The Mentalist and Hawaii Five-0 netted more than $2 million an episode in off-network license fees in their first or second year on the air. Meanwhile, serialized dramas did well in DVD sales but that market died down, and probably the biggest off-network sale of a serialized drama, A&E’s acquisition of HBO’s The Sopranos, only proved that those series don‘t do well in off-network airings. But those same serialized dramas have become major draws in online streaming. And earlier this year, Netflix and Lionsgate TV, producer of AMC’s acclaimed drama Mad Men, turned the traditional off-network model on its head. Netflix acquired off-network rights to the serialized drama for a healthy license fee of almost $1 million an episode in a deal that could be worth close to $100 million. A few months later, the CW parents Warner Bros. TV and CBS extrapolated that model to a full network slate, signing a four-year deal with Netflix for the previous seasons of the network’s heavily serialized dramas that could be worth as much as $1 billion. The pact proved that serialized dramas could be a viable genre even on broadcast TV, whose model is built on repeatability, and established Netflix, along with other emerging streaming services, as players in the off-network marketplace.

Broadcast TV saw the decade-long reign of drama series come to an end this year, while comedy’s comeback, foreshadowed by blockbuster hit Modern Family two years ago, was in full force. Six new comedy series, Fox’s New Girl, ABC’s Suburgatory and Last Man Standing, CBS’ 2 Broke Girls and NBC’s Whitney and Up All Night, received full-season pickups, double the orders last year. On the drama side, only four new series, ABC’s Once Upon A Time and Revenge, CBS’ Person Of Interest and NBC’s Grimm, received full-season orders. CBS’ freshman dramas Unforgettable and A Gifted Man got partial back orders, and ABC’s Pan Am was given one extra episode. While they’re mostly struggling on broadcast TV, dramas are thriving on cable, with several strong ones, including HBO’s Game Of Thrones, Showtime’s Homeland, FX’s American Horror Story, AMC’s The Killing and USA’s Suits, making their debuts this year.

The wave of new comedies brought to an end the domination of male comedy showrunners. Of the 6 new half-hour shows given back-nine orders 5 were co-created or created by women, New Girl (Liz Meriwether), 2 Broke Girls (Whitley Cummings), Suburgatory (Emily Kapnek), Up All Night (Emily Spivey) and Whitney (Cummings). Additionally, Fox’s freshman I Hate My Teenage Daughter, which is still awaiting word on its fate, was also created by women, writing team Sherry Bilsing and Ellen Kreamer, as are midseason comedies Are Your There, Chelsea? (Dottie Zicklin, Julie Ann Larson) and The B**** In Apartment 23 (co-creator Nahnatchka Khan). For comparison, of the 15 returning broadcast comedy series, only 2 were created by female writers, 30 Rock (Tina Fey) and The Middle (Eileen Heisler, DeAnn Heline).

Two And A Half Men was one of an unusually large number of series that changed leads this year. The Office‘s Steve Carell, Law & Order‘s Chris Meloni and CSI‘s Laurence Fishburne all left, with CSI‘s Marg Helgenberger also about to depart. Ryan Murphy took cast changes to a whole new level in his freshman FX series American Horror Story for Season 2.

It was a relatively calm year in the TV networks’ executive suites unless the network was OWN. Rocked by a shaky start, Oprah Winfrey’s fledgling cable outlet dismissed CEO Christina Norman. Winfrey then named herself CEO, while Peter Liguori, who had overseen OWN, including serving as interim CEO, departed the network’s parent company Discovery Communications this month. Elsewhere, the CW transitioned from entertainment president Dawn Ostroff to president Mark Pedowitz. Along with Pedowitz, ABC’s Paul Lee and NBC’s Bob Greenblatt, in their first year on the job, assembled their executive teams, with the most notable hire being Jennifer Salke’s appointment as NBC Entertainment president. In another fallout from the NBC Universal-Comcast merger, Suzanne Kolb was named president of E!, succeeding Ted Harbert, who had moved up. Loaded with funds, Greenblatt and Lee were very aggressive in their first full development seasons, driving up prices in what was one of the most competitive buying seasons ever, full of production and put pilot commitments. In just a week, we will start finding out how many of them will pan out.