Seeing's as the last thread was derailed by trolls into a faeces slinging match. So here's a repost of Ragemore's thread.
IGN, today, carried the official confirmation
IGN: Rock Band 2 this September
of the sequel to Rock Band!
Further details were added by Lead Designer, Dan Teasedale, in an interview also on IGN
IGN: Rock Band 2: The Opening Act
Disappointingly for non-360 owners, RB2 is slated to launch in September worldwide, on Xbox 360, with other platforms getting the game "later in the year."
This is where I am lost. I do not understand why the software for RB2 couldn't launch for all platforms in September, worldwide, with the instrument set for 360; then the RB2 instruments follow later for other platforms. (since the RB2 software is confirmed compatible with RB1 instruments. )
And just to be clear this is the US release date there is no confirmed date for Europe (well EA's three country view of Europe).