Replying to myself, but perhaps this can be useful for someone else.
I got the compilation from source working, in fact I'm posting this through the wireless interface. The modifications to the source file are really really simple.
If you want to try, it goes more or less like this:
1) get the source files from broadcom -- http://www.broadcom.com/docs/linux_s..._82_112.tar.gz
2) make a new directory and extract the source files
# mkdir hybrid-wl
# cd hydrid-wl
# tar -xvzf ../hybrid-portsrc_x86_64-v5_100_82_112.tar.gz
3) change to the problematic file directory
# cd src/wl/sys
4) fix the source file wl_linux.c (of course use your favourite editor):
# vi wl_linux.c
around line 43, remove the line
search for the string
and replace it with
save the file, and try to compile
5) # cd ../../..
If you are lucky things should work, and you'll have a file called "wl.ko" in the current directory. (I got these patches from the internet, not my own work.)
I then did
# mkdir -p /lib/modules/3.4.0-1.fc17.x86_64/extra/wl
# cp wl.ko /lib/modules/3.4.0-1.fc17.x86_64/extra/wl
# depmod -a
# modprobe wl
and I had to reconfigure the interface, inserting the network password again, but after that it's working.