I actually got Buzzed this afternoon. When I was logging into Gmail the splash screen came up and asked me to try it out. I have been futzing around with it today, but will probably switch it off.
Random thoughts on it;
Google seems desperate to get this out; I thought I had been logged out of Gmail when the Buzz splash screen came up as I tried to get to my Inbox. Going a little hard to the hoop, I think.
Along the same lines, it has a big colorful icon next it under Inbox on the left hand menu. Again, seems desperate.
It autofriends some subset of people you know (I think it's people on your Gchat list), which is kind of weird. I logged in and already had one friend following me. It asks to follow your friends as well.
The site ties into some other sites; Flickr, Picasa, and Twitter, I think (that was in the menu that automatically came up). It also lets you connect to Youtube, Google Reader, and Gchat statuses (it looks like when connected activity on those sites will show up on your "feed.")
The status screen screams Twitter and Facebook. I guess there aren't many ways to do 140 character status updates, but it really resembles those sites.
It took me a few minutes to figure how to switch it off; I thought it would be in settings or in Labs, but there's a small link near the bottom of its window and the inbox (where you can also shut off chat). Again, I am glad they have a shut off but hiding it down there seems a bit desperate.
Otherwise there doesn't seem to be much to it yet. I was hoping for some settings or preferences to futz around with (why do I immediately go into a new program's settings or preferences, and why does it always make me so happy?). I am switching it off I think; while I love Gmail, connected sites makes me wonder about how much information Google already has about me and since my Gmail is my general e-mail, I don't need it mixing with facebook-style status updates or anything, and I am creeped out that it uses my name (from Gmail settings, I assume). I realize those can be changed and if I am careful my e-mail and Buzz will never meet, but I'd really rather just not have them together right now.