I've been wondering the same thing: why does it bother me so much that Buzz auto-follows frequently-emailed contacts, but it doesn't bother me that gchat automatically adds frequently-emailed contacts? I think it might be because having contacts added in gchat doesn't mean I'll actually be communicating with them, whereas auto-follow does mean that some communication will take place... I'm not sure though. Also, I guess that having a strictly professional contact's name sitting in my gchat contacts list is different than that person being notified that I'm following them.