Since Activision has announced that Guitar Hero World Tour for the
Wii will feature all the goodies the Xbox 360 and PS3 owners will be getting, Harmonix has obviously decided that they need to step Rock Band 2 if they plan on competing. The new Rock Band 2 will, according to the a Harmonix representative at E3, be "fully featured" for the
Wii. This most likely means that downloadable content, character customization and online play will be amongst them.
This contradicts what Harmonix said about the original Rock Band
Wii, where they claimed downloadable content could not be done due to the
Wii's limited storage space. This comment can now be safely ignored.
Rock Band 2 will release later this year along with Guitar Hero World Tour. The original Rock Band has yet to be released in Australia on any platform, which means a longer wait may be in store for you.
Source:
Harmonix: Rock Band 2 Wii Version Is Fully-Featured | Game | Life from Wired.com