Well, I’ve had a chance to play around with it a bit.
Overall, I’m not particularly impressed. It does what it says on the tin, of course — it handles the functions of email and IM/chat, and if you embed waves in websites, you can do blogs and wikis, etc…. but I’m not really seeing the need to replace all of those separate tools with a single application.
Wave will only turn out to be the “killer ap” if everyone ends up using it instead of email/chat/blogs/livejournal/facebook, etc. …and I honestly don’t see that happening.
Right now, having an “all-in-one” tool is nice, but not really necessary, since the other tools work just fine. I mean, it’s possible to have a combined hammer, saw, screwdriver, drill and spanner, but nobody has bothered to make one since the separate tools are widely used, easily available and well-suited to their particular jobs.
Having said that — I’ve got invites, if anyone out there still wants one. Drop me a line or a comment.