The new lighting engine (and lighting engines used by a lot of modern games) don't support that type of AA, which is why things like MLAA and FXAA were invented to begin with. I agree with you that FXAA sucks, though, and I wouldn't mind an alternative. I know someone in this thread managed to get a different type of AA going, but I can't find the post.
I see.
Yeah, all I really need them to do really is them give us the choice to scale the UI like it automatically does with higher resolutions so I can downsample since most AA methods don't work. Unfortunately, SGSSAA is quite blurry from my testing.