The exec told GameRant that gamer's can expect a big reveal at this year's E3:
[quote]
“Unfortunately I can’t say anything about Rock Band 3 at this point except that it’s coming this fall and it’s a big step forward for Rock Band,” said Rigopulos.

“This has been a two-year development cycle on this title and it’s a pretty significant level up from where we’ve been. We’re pretty excited about unveiling it at E3 this year. Holiday 2010 release.”</blockquote>

In all likelihood, it will probably showcase during Microsoft's E3 conference if past performance is anything to go by. Still, we fully expect the game on PS3 and are excited to see where the franchise goes.