From the Playstation Blog:

If you instantly watch movies and TV shows from Netflix on your PS3, here is the news you’ve been waiting for: starting Monday, October 18 you’ll be able to instantly watch movies and TV shows without inserting an instant streaming disc into your console.
In addition to eliminating the disc, there is a new user interface that brings a much richer and faster browsing experience, content search directly on the device, and dramatic improvements in how fast playback starts.

There is even more good news for PS3 owners: starting on Monday you’ll be able to instantly watch some movies and TV shows in 1080i high definition, listen to Dolby 5.1 channel surround sound, and view an increasing portion of our content library with subtitles. This will bring the home theater experience right to your living room and make instantly watching movies even more enjoyable. Here’s a news release from Netflix and Dolby with details.

No clue as to when new features will become available on other platforms.

PlayStation Blog:
Netflix on PS3: Disc-free Next Week – PlayStation Blog