Didn't give any of the earlier alpha's a shot, and haven't been following the threads all that closely, but don't recall seeing this mentioned yet.
Wifi doesn't seem to work correctly for atheros chips.
lspci shows:
03:00.0 Ethernet controller: Atheros Communications Inc. AR5001 Wireless Network Adapter (rev 01)
iwconfig correctly shows wlan0 as being a wireless interface.
The command:
sudo ifconfig wlan0 up
returns "Unknown Error 132"
EDIT: Ok, so, apparently linux respects the wireless button on my keyboard now, so this is a non-issue, just an unexpected change in behaviour.
EDIT2: Further to this, it seems that if I reboot, I can't enable wireless again. Hard shutdown is necessary if I want wireless network when TC comes back up.