I noticed that udev shipped with Slackware 13.37 picks up firmware in this order:
Firmware files are looked up in:
IMHO, it would make sense to have the firmware in /lib/firmware/$(uname -r). It would be irrelevant to people who use the stock kernel (aside from the necessity to update their custom scripts, if any). At the same time, it would make the life of folks who upgrade the kernel a bit easier, by making the firmware loading a bit more predictable. Moreover, it seems to be the place where Linus thinks firmware should be placed, so it would be in line with the Slackware philosophy.