ya it was confirmed to release a while ago. Supose to be summer-late summer time and they are talking about Rockband 2 for christmas. If it makes it to the Wii aswell I'm not sure.
We are getting the first Rockband thats been confirmed the second one is still rumored for all consoles.
Hopefully they work out the GH/Rockband Guitar issues with the Wii and we dont have to buy extra instruments.