Google Wave has been cancelled by Google. It was a product with tremendous potential that never got off the ground because Google was too busy tripping over their own feet to implement it properly.
The biggest problem with Google Wave was that there was nobody else around to use it with. It was invite only, but even after sending out invites you had maybe 10-15 people you could use it with.
The second biggest problem was that it was completely stand-alone. If you had been able to jump back and forth from within gMail I'm sure it would have seen more adoption, but at the end of the day when you got home to try to use it, it wound up being just one more thing to check.
If Google was really trying to come up with the next FaceBook, they should merge Orkut, GoogleWave, and Gmail into one service.
