I did a sync with Gmail (very excited about this update). I have many of the same people in both my phone and the contacts list in Gmail. Now on the phone I only have a person's name, and in Gmail I only have their email address. After the sync I have multiple entries for some people. And in other instances I have the name of a person, but only their phone numbers (that came from my phone) and the email address (which was in Gmail to begin with) is gone!
Can't provide much more info than that. Just thought I'd pass it on.