I initially went with D-Link DWL-G520 PCI which reportedly has an Atheros chipset but had no luck getting the MadWifi drivers loaded. Gave up and returned that card and got the Netgear WPN311 instead. This card does in fact have an Atheros chipset and the MadWifi driver works great!
The card was a bit more expensive but NO problems at all.
The usual run around with laptops. I loaded the latest Mandriva on my Dell Inspiron 1000. Didn't recognize the Broadcom 1300 (I expected). I was able to EASILY go through the configuration and it prompted me for a source so I put the driver CD in. Had it running in minutes. (with NDIS wrapper)
I don't like Mandriva and I wanted to try Ubuntu. Downloaded the Live CD image and cut it. 5.10. Didn't recognize the Broadcom and the configuration "wizard" was less than helpful. I'm on the CD so I can't source from a CD. On a WHIM I put my Netgear card in. UBUNTU found it during the boot sequence and even was able to update some of the actions from the net while booting/loading from the Live CD.
I don't know about the other Distros, but if UBUNTU saw it straight away, I imagine the more sophisticated ports would too.
ath9k is a completely FOSS wireless driver for Atheros IEEE 802.11n WLAN based chipsets. This driver was released just last week and works with the following chipsets
AR5418+AR5133
AR5416+AR5133
AR5416+AR2133
AR9160
AR9280
AR9281
I initially went with D-Link DWL-G520 PCI which reportedly has an Atheros chipset but had no luck getting the MadWifi drivers loaded. Gave up and returned that card and got the Netgear WPN311 instead. This card does in fact have an Atheros chipset and the MadWifi driver works great!