Will I be able to factory unlock a new AT&T iPhone 6?

I spend about half my year abroad these days and am very excited to buy the new iPhone 6 when it comes out.

I'm curious if I will be able to factory unlock it once I purchase it so I can use any SIM, anywhere in the world.

I will be buying the phone through AT&T, subsidized for $200 or whatever it is priced at. I will remain on contract with AT&T as I have been with them for 12 years now, but would like to unlock the phone immediately after purchase.

Will this be possible? Will it be costly?

Yes you will be able to unlock you iphone 6 which will be working with ios8

I'm sure the phone can be factory unlocked doesn't matter what firmware it's on.