Google would have been far better off launching Buzz as a standalone application. Make it invite only to start, and every single one of the early adopters would be begging to get it. A couple of weeks later give them an option of adding Buzz to their Gmail flow, and most would probably do it and call Google brilliant for thinking that one up. Then slowly bring other users on board over time, as they hear about it and want in. Fast forward a year from now and tens of millions of people may happily be using Google Buzz in their Gmail.
via Google Buzz Warning: Force Feeding Users Can Result in Vomiting
Arrington nails it.