Over the last two months I have been working on the FreeBSD wireless code. Having a single net80211 stack is a huge benefit and the wireless drivers tend to be around 1/4 of some other operating systems. The driver is an interface to the hardware and leaves beacon processing, state changes, encryption, scanning/roaming and so on to net80211.
Sam committed a large set of net80211 changes that brought in revamped scanning, background scanning/roaming and changes needed for 11n. As part of this I worked on the iwi, wi and ndis drivers and there is also a pending update to ipw. Hopefully people are testing their setups, the 7.0 BETA is coming up soon which will give the code even more exposure.