Hulu’s rumored premium HD service became a reality today with Hulu Plus, a $9.99 per month subscription. Hulu Plus allows you to watch every episode from the current season (and past seasons of select shows) from ABC, Fox, and NBC. Normal Hulu users are limited to the most recent episodes. Hulu Plus works on the iPhone 4, 3GS, and iPod Touch 3G running 4.0. The iPad version works over WiFi or 3g.
Hulu Plus is invitation only at the moment, and you can request an Preview Invite here. When the service will go public is unknown, but for those who have managed to get an invite, the App is available through iTunes. Sadly, the service is still ad-supported despite the monthly cost.