We’ll know soon enough whether this is a blip, or a trend. But Wall Street clearly has serious concerns about the fate of the pay TV business after Disney last night trimmed its cable financial forecast based on subscriber slippage at ESPN.

The Dow Jones U.S. Media Index is down 4.6% in early afternoon trading.

And Big Media companies are among the hardest hit: Discovery’s -9.5%, Time Warner’s -8.7%, Disney’s -8.6%, Viacom is -7.8% (and touched a 52-week low), Fox is -7.1%, Comcast is -4.7%, and CBS is -4.5%.

CBS and Fox report Q2 earnings today after the market closes.

More broadly, DreamWorks Animation is down 11.9% after its disappointing earnings last night. Others hard hit include Madison Square Garden (-6.7%), AMC Networks (-6.7%), and Scripps Networks (-5.1%).

Why would Time Warner shares suffer after it reported better-than-expected results from Q2? “Affiliate fees are the core element of most [Time Warner] long theses,” says Bernstein Research’s Todd Juenger. “Any increased risk to Turner’s double-digit domestic affiliate fees is a problem for [Time Warner] stock.” Although he believes cord-cutting “will not be severe.” he adds that “every day that goes by it seems the risk is increasing, not decreasing.”

The latest variation on the cord cutting theme: Distributors including Charter and Verizon are interested in creating so-called skinny bundles, that would cost less than the full expanded basic pay TV package but with fewer channels. Those left out could “suffer dramatically,” Charter CEO Tom Rutledge said yesterday.

Dish Network CEO Charlie Ergen said today that the balance of power in TV “has totally shifted to Netflix” whose stock is up 2.3% today and touched a new all-time high of $129.29. “Nobody is even close.”

He sees the change most clearly in kids’ programming. That “used to be right up in the 2, 3 or 4 things people watch” on Dish, Ergen says. But now kids prefer Netflix, where they don’t have to deal with ads. And it’s “irrelevant” whether an episode of a favorite cartoon is new. “They can watch an episode of SpongeBob from 2007.”