Recently got the Rock Band 2 SP Bundle. This includes a wireless guitar, wireless drumset, USB Mic and the game disc itself.
I was very apprehensive about getting RB because I had tried it earlier (in Boston) and since can actually play a real guitar the plastic one from RB just feeled very disorienting. However RB has another ace up its sleeve and thats the drums.(Am not much of a singer)
The Drums are awesome once you get the hang of it. In fact once you get real good at it there also additions like a cymbal expansion kit which can be connected. (Yes, I know that I probably sound like a drummer/geek combo by now)
Also the Rock Band music store helps since they have a HUGE selection of tracks, thus more add-on content. (Drumming gets especially difficult on the Metal tracks when the double bass kicks in). I generally do not mind paying for RB music tracks since I have pretty much ripped all my music so far from a million sources(poor student days) and so its only fair that I pay for this when I earn now.
There is another feature that most people are missing when they try RB. This isn't about how good you are on each of these 'instruments' , its about getting together, having fun and hitting the right notes. (Just like DDR isn't about how to dance but rather about hitting the right notes) Another thing that a lot of folks are missing is that RB is just another way of experiencing some good music (only this time its much more interactive). This makes RB all the more popular for kids who are starting out to explore the amount of music available out there and not just listen to Britney, Christina but rather go onto Deep Purple, Beatles, Rolling Stones. (Too bad Floyd, Zeppelin haven't released any of their stuff yet)
For now lets get back to drumming some more and hopefully get the cymbal expansion kit sometime.