Debating buying Xperia... Can I debrand/root on a Mac?

[Hartattack]

I can't seem to find this answer anywhere. I'm about to sell my Blackberry Torch cuz I'm over it! So within my price range I found a brand new white Xperia x10a for At&t. Now my question, I want to be able to upgrade it to the 2.1 update but I know the phone needs to be debranded... I think? So I only own a MacBook Pro. What do I do from here?