I think Buzz's most fatal flaw is that it relies to heavily on Gmail. Anybody who hasn't used gmail until now will probably not start using Buzz. Another thing

I think Buzz's most fatal flaw is that it relies to heavily on Gmail. Anybody who hasn't used gmail until now will probably not start using Buzz. Another thing (but that's very imho) is that Google applications still look and feel like Excel. They are certainly very good, but also feel like work.