I have a lot of people who are in both my gmail contacts & on facebook.
It's beneficial for me to have people's google acct be their primary because I have the contacts app sort by companies. I'll give you a scenario to illustrate.

I just replaced my ailing Pre. Activated my new Pre. Brought in google & fb. Ridiculously, all of my contacts who have both end up with fb as their primary acct. That means they don't show up sorted in the proper company until I go in and manually set default for every single one. Halp. What could we do about this?