May be sad, but it is a chicken and egg problem: AMD doesn't support Linux properly, so I won't give them my money. AMD does not have money, so they don't support Linux properly. The problem here is that AMD does have no money because their marketing guys and the people in their headquarters are morons.That's sad because then you don't give them money for their open source driver than either.
I will mostly run older games on that machine /Serious Sam First/Second Encounter, ...) and not so demanding games (Civilization IV, ...), so the performance of the newer Intel GPUs is more than sufficient for me.Intel graphics is actually pretty good. While many people complain about team fortress 2 not running with decent performance with amd gpus it runs very well with ivy bridge. Counter Strike source is well playable too, but it has still some rendering errors (sometimes flashing artifacts). Trackmania nations in wine and flatout 2 in wine work very well too. Of course not with antialiasing, but it works. If you wait for the next gen intel gpus, it will be quite usable for many games I think.