Like Jordan, I was able to re route the cables to successfully install the newer wifi AC card in my late 2010 13" Macbook Air. Snipping the antenna cable from the hinge part was the scariest thing, but after that I had _just_ barely enough cable to plug into the card. The card is of course too long to screw in.
I'm happy.
Have yet to test with a wireless AC router to see the performance boost I get.