Along with extra TV shows, Hulu Plus is far more accessible with applications already available for the Apple mobile devices like the iPad, iPhone and iPod touch via Wi-Fi or 3G, as well as Web-connected Samsung HDTVs and Blu-ray players. Support for the PlayStation 3 is expected in July, while the Xbox 360 will get Hulu Plus early next year. The service is also "coming soon" to Vizio and Sony HDTVs and Blu-ray players.
If you're interested in signing up, you'll have to request an invitation here. The site says it will issue invitations in waves over the coming months to ensure it's offering the best experience for members. Here's a more complete look at the library of shows included with Hulu Plus. It's worth noting that the basic free version of Hulu you're probably familiar with is still available and unchanged for now anyway.