Buzz sounds pretty exciting. Some of the geo-tagged updates sounds really slick. My first reaction - this is going to be 'public follow' thing more than a 'follow my friends' things. Because emailing my friends is like, so 2007!
Fact is, I don't email my closest friends/family anymore. I either IM them, post on their Facebook page, send them SMS or call them. Email is more for work type, non-personal stuff. Having said that, it's important to note that Google does have GTalk and Google Voice so I hope they weigh activity from GTalk and Google Voice higher than GMail activity when figuring out who I must 'auto-follow'.
Time for someone to write a Buzz-to-Facebook cross poster. :)