I was able to install the mid 2013-early 2014 wifi/bluetooth board into a late 2010 13" Macbook air. Bluetooth and Wifi are still working. I have yet to see what the performance gains are.
I was encouraged by the fellow who tried it here:
https://www.ifixit.com/Answers/View/183530/How+can+extend+airport+antennas#answer185770
Some snipping of things is required to make the cables just barely reach. Cannot screw the card into the motherboard.