I have been keeping my eye on this. The results are slowly coming in and it may be the first upgrade in a few years to the tired old onboard nic you have currently.
This initial test improved framerates and dropped pings down.
This is exciting stuff! Imagine prioritizing your gaming traffic over your teamspeak traffic. Then you don't have to worry about communication software affecting your game performance.
I'm seriously looking at adding this to my next game machine build along with the AGEIA PhysX card.