What is Google Wave good for? I don't know! I haven't used it. Above, two Google Wave demo-tainment videos you must watch. YouTube hacker/artist Joe Sabia has done it again. Two Google Wave experimental films, Pulp WAVE Fiction, and Good WAVE Hunting.
And, more soberly now: in an extensive feature-by-feature blog post, Daniel Tenner breaks down what purpose Google Wave serves, and why early detractors may be missing the point.
I believe this is partly Google's fault: they released Wave to geeks and hackers and social media folks first. But Wave is not a geek/hacker tool, or a social media tool, it's a corporate tool that solves work problems (more on that later). On the other hand, they never claimed it would be a Facebook replacement or a Twitter killer. Google calls wave an "online tool for real-time communication and collaboration". The way Google should have advertised Wave is: "it solves the problems with email".
What problems does Google Wave solve? A matter of perspective. (danieltenner.com, via @carr2n)