I have an ASUS K73S working with Debian Wheezy-sid distribution. When I launch 3.8 linux kernel (3.8.1, 3.8.2) the WIFI does not work.
After some researches, I found the the kernel doesn't build atheros drivers (ath5k, ath9k and carl9170) The options aren't enabled for compiling them.
I did more researches. I had to reactivate the following option : Device drivers-->Network device support-->Wireless LAN-->Atheros wireless cards. Activated with the previous 3.7.x kernel version, this option is desactived with 3.8.x kernel version.
This is a simple configuration issue, nothing to do with ath9k, so this bug can be closed.