Only the clear cover, LCD screen and what memory you have won't work with the GP3 (uses MicroSD). All the other mounts and clickers work the same (the base hasn't changed, just the case the camera goes into). You can re-use all the sticky mounts, or whatever else you have.
If there wasn't that Silver bundle I would have taken the Black and sold the wifi remote ($79.99) to off set the cost.
I'm pretty happy with the Silver version, I'm not going after theatre/professional quality videos (or have the hardware to run those insane resolutions lol... $30,000 Sony 4K tv? I don't think so). Having 1080P in 48FPS would be awesome, but it's TONS better than the GP1 I had. They took the $329.99 extra battery/chest mount Silver bundle off the website, but ask for it in-store, just look for a white box where the Go Pros are sold.
PS: I don't even see the GP2 on the BB website anymore.... ?
Cool video: fix car dents with your go pro suction mount!
http://www.youtube.com/watch?v=kpm7ewSU-to&feature=g-u-u