Update: It appears that Rock Band Wii will also lack online play. Possible explanations given were that your rockitude levels were too badass for the Wii's hardware.
Harmonix announced Rock Band for the Wii! Fanfare and trumpets! You can get your rock on come June 22nd, with a special edition package set to include drums, a guitar, and a mic for $170. The game will ship with 63 songs in the tracklist, and of course will feature the option to download weekly content. Wait, that's what would have made sense. Oops, I got a little carried away, there. The game will feature no downloadable content, no mii support, will NOT support the wiimote integrated into instruments (which means you can't use your GH3 controller), and no character creation. The Band World Tour mode hasn't been commented on, but since it was said to have a similar feature set as the PS2 version of Rockband, I wouldn't count on it. All the instruments (except for the guitar) will be wired, and it will ship with a USB Hub. So.. uh.. get your rock on, I guess.
Read More. In other news, my PC is up and running, and it's a behemoth now. Although my wallet is a little hurt because of it.