I finally got my account on Google Wave "Preview" version a few weeks ago. I invited bunch of techie geeks like myself and now we wave. Right?! Wrong!!!! People just don't know how to use it. Wave's email doesn't work. So if you want to email me at enoch.moses[at]googlewave.com then it will get bounced back. There attachments functionality does work yet . I tried sending a descent sized PowerPoint slide deck and I believe it is still loading. Wave folder functionality doesn't work. I guess most of the stuff doesn't work because it's a "Preview" version. I would rank Google's "Preview" version as Oracle's "Production" version. Stuff is supposed to work but it simply doesn't.
I do like the concept and I tried to wave but no one waves back because you really cannot wave. Not even blip well. So get an account and be patient.