Just logged in and it asked me if I wanted to go straight to Buzz.

Went straight to my inbox.
But had to un-subscribe by default to following my contacts and had to change my profile to private to stop others following me.
Bit of a hassle, but at the moment to big worry, just a minor inconvenience.
If it gets more intrusive by default as Buzz (if) grows larger then I would defect but it seems okay atm.