Initial impressions
- The modules make it really easy to edit content
- No real way (besides email) to search for friends
- The modules are really geared to “fun” and “personal” (not business)
- Can edit background images and module colors easily
- Search box is for the web only
- “About Me” is obnoxiously cute
- There’s a Mash Pet
- One module allows you to see who’s visited your profile
- Can add you existing blogs by RSS feeds (by module)
- There’s a Twitter module
- The “Ego Boost” module uses your name and your friends

I’m sure that this is the initial release and that more is on the way. It’s going to be interesting on how quickly they adopt testers (users) suggestions. There’s not a lot of viral content and it’s not easy to build your network – which is the quickest way to turn off your users. But this is Yahoo! and I’m willing to give them the benefit of time.

If you’re interested in joining the Y!Mash beta – leave a comment!

EDIT: Brian Solis at PR 2.O has a much more detailed write-up.