There have been more than a few games that have released with issues enabling AA on ATI hardware (espeically on X2 and crossfire configurations). This is not an unusual issue by any stretch of the imagination.
I will be disappointed if it is not fixed by launch, but I consider it a low priority issue in the grand scheme of things.
Those "issues" are often agreements between nvidia and the dev. However, I would be happy if cryptic could sort that out asap
There was a nasty bug found with ATI video cards and AA enabled. Some of the visual effects started acting like strobe lights that just sucked all system resources until the system ran at a snails pace. Even on machines that had monster video cards the effect was so large it filled the screen making it impossible to see anything else while it was going on.
Yup, I experience this even on an NVIDIA card during closed beta. I didn't find out this was the root of the problem until I started playing around with graphic settings. It was much worse in ground combat.
But if you use bloom effects and dynamic lighting, you really don't need AA since some edges will be smoothed due to lighting (since bloom and dynamic lighting are post processing effects). And I've seen bloom and AA fight each other in some game engines.
I usually run AA off now in most games. It was useful back in the days, but just gets in the way most of the time now.