Hello,
I just installed Kamikaze 7.09 with X-Wrt Extensions in a WRT54GS v2 (Broadcom BCM4712 chip rev 1).
WAN and LAN apparently work fine. I can not make WiFi work.
The wireless configuration is:

config wifi-device  wl0
        option type     broadcom
        option channel  11
        option disabled 0 

config wifi-iface
        option device   wl0
        option network  lan 
        option mode     ap
        option ssid     OpenWERT
        option encryption 'wep' 
        option hidden   '0' 
        option key      '1' 
        option key1     'xxxxxxxx' 

Here is what I get when I run "wifi detect" and "wifi up":

root@OpenWrt:~# wifi detect
broadcom: Detect failed

root@OpenWrt:~# wifi up
No Broadcom wl interface found!
No Broadcom wl interface found!
ifconfig: SIOCGIFFLAGS: No such device
ifconfig: SIOCSIFADDR: No such device
No Broadcom wl interface found!
wl0(broadcom): enable failed

Maybe I missed some module in the installation?
I will appreciate any idea.
Thanks.

Make sure you use the 2.4 version of kamikaze, which has an older, proprietary version of the broadcom wifi driver. The kamikaze broadcom 2.6 release has no wifi, the opensource driver is currently in development.

Thanks for your answer.
I think you are referring to the Linux version, dmesg reports 2.4.34. 
I am not familiar with this software, this is the first time I try to use OpenWrt but I think is missing some module.
Here is the output of ls mod:

root@OpenWrt:~# lsmod
Module                  Size  Used by    Not tainted
ip_conntrack_tftp       1712   0 (unused)
ip_nat_irc              2336   0 (unused)
ip_conntrack_irc        3128   1
ip_nat_ftp              2960   0 (unused)
ip_conntrack_ftp        4272   1
ppp_async               8044   0 (unused)
ppp_generic            22380   0 [ppp_async]
slhc                    6064   0 [ppp_generic]
switch-robo             4540   0 (unused)
switch-core             4864   0 [switch-robo]
diag                   25520   0 (unused)

And here the output of iwconfig:

root@OpenWrt:~# iwconfig
lo        no wireless extensions.
eth0      no wireless extensions.
eth0.0    no wireless extensions.
eth0.1    no wireless extensions.
br-lan    no wireless extensions.

Thanks again.

Weird indeed. I have a Wrt54-GL and have the module kmod-brcm-wl installed, but it seems to be unused from lsmod.
You could try to load this and see if that helps. What's the dmesg output?