It’s been long desired by PS3 users to be able to access the XMB in game. If the rumors are true, the wait may soon be over. According to some users on the official EU PlayStation forums (here and here), there’s a lot of cool new stuff coming in v2.0.

Presently, 64MB of XDR RAM, 32MB of GDDR3 VRAM, and the entire 7th SPU are always reserved for the XMB even during games. Firmware 2.0 will reduce the memory usage to 32MB of XDR and NO GDDR3. XMB will still run on the 7th SPU but the 7th SPU wont be reserved, other things can be run on the SPU besides the XMB.

That’s a LOT of memory being freed up if this is true. 32MB is a good number for the XMB to run with, so this could prove to be useful for future games running better.

Firmware 2.0 will have in-game XMB.

Not all of the icons will be available on the XMB during a game.
Under ‘Friends’ there will be ‘Block List’, ‘Add a Friend’, ‘Players Met’, ‘Message Box’, and all of your friends. Your friends’ avatars will not show in-game in order to conserve memory.
Under ‘Network’ there will be ‘Download Management’.
Under ‘Game’ there will be the disk icon with the title under it. Selecting this will prompt you for quitting the game.
The ‘Video’ column will not appear.
Under ‘Music’ there will be all of your sound files. You can play any of them and they will continue to play after you exit the in-game XMB. You will not be able to delete any of your songs in-game.
The ‘Photo’ column will not appear.
Under ‘Setteings’ there will be:
-’Game Settings’ wich will include ‘PS/PS2 Upscaler’ settings and ‘PS/PS2 Smoothing’ settings.
-’System Settings’ wich will include a new subsetting called ‘Turn Off the System’.
-’Date and Time Settings’ wich will include all the normal features.
-’Accessory Settings’ wich will include all the normal features.
-’Display Settings’ wich will include everything except ‘Video Output Settings’.
-’Sound Settings’ will unclude everything except ‘Audio Output Settings’.
The ‘Users’ column will not appear.

Very detailed information. This did come from a forum, so take it with a grain of salt. But somehow I wouldn’t be too surprised to see this added in the near future.