At www.socalfreenet.org we use m0n0wall exclusively in our gateways and 
also 1.2b7 in some dual APs (802.11a backhaul, 802.11b AP).

We would be happy to test any FreeBSD 6.x candidate builds in some of 
our deployments. There are two classes of testing that I think this 
would suit well:

Gateway:
+ load stability
+ basic traffic shaping ability
+ dhcp LAN services
+ simple captive portal ('click here to agree')
+ either static IP WAN or dhcp
+ dyndns loging
+ syslog

AP:
+ 802.11a client
+ 802.11b AP (prism or atheros)
+ dhcp on LAN (802.11b)
+ simple captive portal
+ verify the fixing of several known bugs in 1.2b7, e.g. prism 600k 
throughput limit, prism hang (standby mode bug?)

We would not be in a position to provide much in the way of debugging. 
Also, as this is a live system, in the event of instability we would 
have to pull the CF and replace with a stable system. However we could 
provide remote access and syslog access.

Hope this might help!

cheers, michael