Has anyone considered doing something like this? I'm entertaining the idea of modifying /etc/init.d/tc-config to do exactly this. At the moment, I'm running purely from multiple initrd-loaded CPIO.GZ archives with the fresh .dep files from the repo. I'd like to rebuild those deps based on the running kernel before tce-setup does its dep check. The advantage of this is that I can have one set of CPIO.GZ files and just swap out the kernel/root/kernel modules at boot time from 32-bit x86 to 64-bit x86-64 (aka x64).
I'd figure there may be a desire to also do something else so I'd consider doing it just after the parsing of /proc/cmdline.