I tried b43-openfwwf from the URL above. It works with gentoo-sources-3.1.10-r1 deblobbed, though it's unstable -- got a kernel warning, then a freeze on after resuming from hibernation (following a 'modprobe -r' attempt). It would be nice to have an official gentoo ebuild to foster more testing.
Related dependencies here (I actually needed only b43-asm as b43-fwcutter was already installed):
Does anyone actually use the openfwwf for more than a few days before switching to the closed firmware? Last I checked the open firmware was missing a few features that basically make it unusable for a very high percentage of users.
If someone actually comments that it's usable, I'll move it to the gentoo repo.