I loved google wave -- it was great and ahead of its time. I think it was a major mistake that google let it go and that the apache wave foundation never got it going. it is too late now but really a greatly missed opportunity.
(2) It tried to be an all-in-one comm platform, and because of that it excelled in none of what it tried to do.
(3) Poor UI performance was the death sentence of it. If you can't use it fluently, it's not good for real-time. Poor UI design did not help, on top of that.
It was an interesting experiment, but not all experiments end up with a successful product. I hope the ideas will be unearthed at some moment and reused with a greater effect.