Despite the fact many parts of Europe are only just getting Rock Band 1, a PR company hired by EA to handle the series has told Eurogamer that the UK can expect to see Rock Band 2 "this side of Christmas". EA UK proper have of course since denied this, saying a date is yet to be announced, but that sounds more like ass-covering than genuine ignorance.
On a related, sad note, I put money down on a preorder for Rock Band 1 yesterday. Release date of November 7. 2008. It'd be great if by, oh, Rock Band 3 MTV and EA could get their shit together on these non-American launches.
Rock Band 2 "this side of Christmas" [Eurogamer]