Rock Band 2 on Xbox 360 for $90 and $70, respectively. Of course, the bundled Xbox 360 guitar with the original Rock Band was tethered to the console and the drums were wired on all platforms, so we're hopeful this means the instruments included in Rock Band 2's big bundle will all be wireless. A Harmonix representative informs us that no prices, shipping dates, colors, astrological signs, or further details concerning Rock Band 2 will be released until next week's E3.
Source - Rock Band 2 wireless drums
Source - Rock Band 2 wireless guitar