I’m in bed with some kind of virus and was thus sufficiently bored to actually watch the entire Google Wave Demo. It’s a very impressive demo and a very nice piece of technology, and it’s being implemented in an idealistic fashion.
The big problem with it is that it isn’t backwards compatible with email. I would have thought that being able to interoperate with email would have been a major priority, but in fact the only mention of it was a half-mumbled remark towards the end about how it would be nice if someone wrote an extension for this. It’s especially odd that this issue didn’t get dealt with more explicitly, since Wave is explicitly intended to replace email.
It’s interesting to imagine what a conversation between a Wave user and a conventional email user might look like — either the email user is going to lose all context each time he/she gets a reply, or the Wave user is going to get a distinctly un-Wave-like mess of pointlessly quoted crap.