Yeah I know, we've been playing with it at work for a month or so as part of an internal collaboration project. I think it's great conceptually, but I still think they should have added some kind of gmail or gtalk notifications with it during the beta. (right now a big negative is the need to go out and check yet another account).

Although, Google Chrome (browser) just had extensions released for it (beta channel only) which are awesome, things like IE tab and wave extensions that will display notifications when new waves pop up, plus tons of others... If you guys run chrome beta/dev version I'd recommend looking into them, they are pretty sweet.