Sony spokesperson Paul Purdyconfirmed at the 2008 Consumer Electronics Show that in-game XMB is coming to the PlayStation 3 this year, according to the source linked above.
The rep unfortunately would not pin a date or give a release timeline, but rest assured that the long-awaited feature is coming this year guys! :D
For those unaware, the PS3's OS is unavailable while in games. This prevents the use of custom soundtracks or messenging while a game is active, and since the Xbox 360 offers its users both while in-game, PS3 owners have been justifiably frustrated.
This should have been a feature from the start, especially from the video clips they had from long ago that already showed the in-game XMB. However, I'm very happy they decided to deliver it regardless, and can't wait to be able to change my settings while playing. It sure beats having to play, then quit, change the PS2 settings, and then hit play again, while all the time making sure the controller is active so I don't have to suffer more of those terrible audio problems my HDTV was having...