Well i've finally got my invite through for google wave and my first impressions are great. Although when my account was activated I had no extensions and when I tried to load the extensions gallery I had "Dr. Wave" telling me to refresh my page, But this is very beta software so it is understandable that things could be broken.
Alot of the development work I do is all remote - so having software that improves communication is always welcome for a trial, and google wave ticks alot of my boxes. Having the ability to collaborate on a joint "wave" between multiple contacts makes writing specifications and requirement documents much easier as you can create a "blip" on any part of a current "wave" message and add amendments.
Once you are happy with the final copy - you just select it and click "make into new wave" and you have a clean version of the final document with no comments on it (whilst keeping the commented one too)
There is a very handy firefox extension which enables you to have the "wave" page closed and still be notified when you have a new wave.
Google Wave is missing email notification upon receiving a new wave - i'm not sure if this will be introduced (as it could become quite spammy) but the notification plugin is brilliant.
Once my extensions were turned on again - I was able to give them a good test. The initial google extensions look very good and show just what google wave is capable off, with collaborative google maps: giving the ability for all participants in a "wave" to add markers to a map & add items to an itenary all in real time.
Google Wave is a fantastic insight into where the web is going.
Lots of good things to come