Yes sir, Harmonix will be releasing a standalone drum set and wireless guitar that, according to folks at Amazon.com, are set to release alongside the special edition Rock Band 2 bundle and software in September. That means, unlike the original Rock Band, you won't have to wait months after the game's release to buy standalone peripherals. Both the drums and guitar (again, all boxed up) are $10 more expensive then their Rock Band brothers, with the drums retailing for $89.99 and the guitar retailing for $69.99. Ouch ... we know. While you ponder whether or not a wireless drum set is worth $90, we advise just sitting back and admiring their retail boxes. They're so boxy, so blue, so Rock Band inspired and so damn expensive.
Source - Rock Band 2 wireless drums
Source - Rock Band 2 wireless guitar