The thing that interests me is peoples response to innovation.  It takes time for people to work out how to use new systems like this.  The more flexible it is the longer it takes people to blend a culture around it.  Wave does remind me somewhat of having my first phone that could send a text, and only having one other friend with a similar phone and the will to use it.  Lets hope google get the bugs and interface ironed out soon though as I think its going to be a fun way to colaborate.