As a college student who doesn't have a ton of money (and space in my dorm), this news makes me eccstatic. According to Game Life, Activision announced at their E3 conference that your Rock Band 1 instruments will work with the new Guitar Hero: World Tour. Please note that this announcement was only made for the Xbox360 so, as a PS3 owner, I hope they will announce this for Sony as well. I see no reason why they would not do this, but hey, you never know, I've seen dumber video game decisions.
But wait, doesn't the new GH:WT instruments have five drum pads? Yes, the new drum pads from Activision has 5 inputs instead of Rock Band's 4. However, the game will accommodate the change by having the on-screen gameplay only have four colors.
However, there is incentive (though not much for my budget) to get the new drum set from Activision. Their drum set has a MIDI jack that will allow a user to use his or her own electronic drum kit, if you have one. You'll also be able to put in a second bass pedal and be able to use it in the game.
To even sweeten the pot, apprently Xbox came out with an auto-dowdloaded update for Guitar Hero: Aerosmith that allows the user to use a Rock Band guitar.
The consumer has won! Victory!