I think we should not compete google buzz with twitter and facebook because it's have different platform to generate traffic. I don't think it can be compete twitter or facebook in coming months in traffic.
I don't believe the web traffic from Buzz will be capable to fight with the web traffic from Facebook or Twitter, as Buzz's major downside is that it’s an integrated division of Google and can't be alienated from it and as a result in countries where Google isn't well-liked Buzz will not be able to grow up to a large extent.