A question from AJ reminded me that I haven't said much about the changes to packaging of firmware in Debian, and in particular the separation of non-free firmware from the Linux kernel.
There is an ongoing process upstream to move firmware blobs from drivers into a firmware/ subdirectory of the source, which is now almost complete. Since most of this firmware is non-free, we remove it from the source tarballs for kernel packages but use it to update the firmware-nonfree "source" package.
We continue to patch some drivers to separate out firmware, and have been submitting our changes upstream. Most of these have been accepted though the DRI drivers matrox, r128 and radeon are notable exceptions.
A few months ago I attempted to make a new inventory of the remaining firmware blobs outside of the firmware/ subdirectory. I identified three that should still be addressed. The Linux-libre project, however, removes many other constant arrays from the kernel (and disables the affected drivers) where I judged the array to be a plausible preferred form of modification.
Much of the non-free firmware removed from the kernel is now available in the firmware-linux package in the non-free section of the Debian archive. Starting with Linux 2.6.31, we will build the DFSG-free firmware shipped with Linux into a package called firmware-linux-free, which will be recommended by kernel image packages. The contents of firmware-linux will be moved to firmware-linux-nonfree and firmware-linux becomes a meta-package depending on the other two packages.
Many other firmware images never distributed with Linux are also packaged for the benefit of users that require them.