Last I heard, radio firmware pretty much had to be locked down or the regulators wouldn't certify you; the principle here being that as all modern radio chipsets are basically software-defined radios, they're indistinguishable from incredibly effective jammers. They consider the right to dial emergency services on a cell phone and have it work to be more important than the right to play with hardware.

So I'm interested to see that there's actual open source firmware for the ath9k, and it looks like the hardware will accept unsigned firmware images. Have the rules changed? Or are the regulators simply less concerned about wifi relative to mobile phone radios?