Would it be alright for kernel packages to provide for others that depend on in-kernel features/functionalities, say, those from patches? Right now kernel26 has the linux-phc patch, and the following is a GUI tool to do what can be done, well, graphically: http://aur.archlinux.org/packages.php?ID=17059
As you can see, it could either skip the kernel26 dependency and tell the user about the patch in install script - or - include the dependency like the above case and expect the user to adjust PKGBUILD for other kernels with the same patch.