Watching TV shows online has become the norm for young viewers, and most networks have embraced that. (The CW even started selling spots in full episodes of its shows streamed online this past upfront as part of “convergence packages”). But there have been two notable holdouts, Fox’s American Idol and So You Think You Can Dance, whose episodes were not officially available online. Fox just announced that for the first time ever, it will stream full episodes of SYTYCD on its Web site on a four-day-delay basis (they’re also available on hulu). Will Idol be next?