AA for NVIDIA is possible with nHancer and looks very nice.

Use the Vanguard setting and AA settings like this:

http://www.nonflamersguild.com/galle…geViewsIndex=1

http://www.nonflamersguild.com/galle…geViewsIndex=1

http://www.nonflamersguild.com/galle…isen3.jpg.html

Addition:
If you have enough graphic card power you can use 2x2 Supersampling instead of Multisampling. This works wonders against the flickering grass.