MTV Games has confirmed the Wii version of Rock Band 2 will offer downloadable songs in the future.
Incidentally, there was no word on how MTV Games and Harmonix plan to cope with the limited storage capabilities of the Wii - perhaps they know something we do not. Activision is making do with the limited on-board storage and SD cards for DLC in Guitar Hero World Tour.
MTV Games also revealed that Rock Band 1 discs will be sold "indefinitely", according to Variety. This means songs from the first game are unlikely to be bundled online for Rock Band 2 owners any time soon.
But all the songs from the Rock Band 1 disc can, of course, be transferred into the sequel for a small charge.
Rock Band 2 was released on Xbox 360 in the US earlier this month. PS3, PS2 and Wii versions will be available before the end of the year. There's no release date for Europe, as yet.