Trying to answer a few questions I have seen here... We signed up two weeks ago, and have the "8.99 1 Disc at a Time, Unlimited" plan. This is the bare minimum to request the disc for streaming.
When you go to Netflix, sign in and go to the main page. Across the top banner, click on INSTANTLY TO YOUR TV. Scroll down just a bit and you will see the NETFLIX READY DEVICES banner, which displays the Xbox 360, PS3, and Wii. Click on the Wii graphic and it will take you to the sign up page.
The streaming library is pretty extensive. THAT SAID, they do not offer the brand new movies for streaming. But there is a ton of movies and TV shows available for streaming, whether you go to your laptop or use a device like a game console or Roku box to display on your TV. Movies/Shows that are available for streaming will give you the option to watch now or add to a Streaming queue. Hope this helps all of you lucky Netflix folks.