Photo: Hulu

FORTUNE — Like many Hulu Plus subscribers who use the $7.99-per-month service to catch up on TV shows they’ve missed, I have no shortage of ways to get it. It’s on Roku, PS3, XBox and the Wii. There’s a Hulu app for the iPad, the Mac, Linux and Microsoft MSFT Windows. It even came pre-loaded on my Internet-ready Panasonic HDTV.

But as Walt Mossberg pointedly reminded Tim Cook at D10 in May, it wasn’t available on Apple TV.

Until today.

What happened?

Hulu’s announcement doesn’t say, and Apple AAPL didn’t even bother to issue a press release.

But Peter Kafka, AllThingD’s media reporter, offers a couple theories that ring true.

  • The likely hang-up: Apple’s insistence that it get a 30% cut of Hulu Plus subscriptions purchased through the Apple TV. When you sign up for the service on Hulu’s website, Hulu keeps the full $7.99 monthly nut.
  • What changed: The arrival of AirPlay in Mountain Lion last week meant that Mac users could start watching content from Hulu’s free website on their large-screen TVs without paying a monthly bill. That’s not something Hulu’s owners — Disney/ABC DIS , Comcast/NBC CMCSA , and News Corp./Fox NWS — or their partners could long abide.