So I'm trying to get bootsplash working. I've got everything in place except the kernel. So I apply the patch, reconfigure the kernel to add support for bootsplash, do make-kpkg kernel_image and install the .deb over my existing 2.6.11 deb. I leave the modules in place too since I figure there's no need to recompile some of them, since I'm just adding stuff. So I install the image, and reboot.

The bootsplash doesn't work. So use "splash" to try to load an image on the go and it tells me /proc/splash doesn't exist. I do a uname -v and get this:

tom@furstation:~ $ uname -v
#1 Mon Apr 11 20:07:15 CDT 2005

Now that's a bit odd, since I just compiled it today [May 9th] and installed it. Anyone?

Not sure what you mean by installing a kernel over an existing one. You add a kernel with dpkg and have to remove the earlier one also with dpkg. Is the line in lilo.conf or menu.lst pointing to the new vmlinuz and did you run lilo after adding the kernel to the bootloader?

So do I need to remove the current kernel-image-2.6.11 and install the new deb? (and yes, my menu,lst points to the symlink /vmlinuz, which is also correct)

Well, you can't remove a running kernel or install a new one over it. I suggest you look at the sticky about compiling kernel 2.6. Basically you do:
fakeroot make-kpkg --append-to-version=.21345 kernel_image
Change 21345 to todays date or a name of choise.
Add the new on to menu.lst but don't remove the old one. Always a good idea to have two kernels if something goes wrong with the running one.