Install kernel26ck thru pacman. reboot into kernel26ck and ran into many errors such as ndiswrapper modules not found, cups commited suicide, and failed to start xorg server. Right now i'm back on stock kernel.
:-( did I do anything wrong?
The only issue of those three that I can respond to immediately is your ndiswrapper problem. You will need to rebuild the ndiswrapper module for kernel26ck - the best way to do that would be to get the ndiswrapper-beyond PKGBUILD and install files, change pkgname to ndiswrapper-ck and _kernver to 2.6.17-ck, and build/install the package.
For cups and xorg, please post error messages and anything else you think is relevant.
Do you use the nvidia or ati driver packages? If so you need to install them for the ck kernel. Modules are installed on a per-kernel basis. So even though you've installed the modules for the stock kernel they don't exist for the ck kernel. If you use nvidia, a nvidia-ck package already exists in community. Ati has to be build with abs if you need it. If you're using any other extra modules, tomk already mentioned about ndiswrapper, you'll need to build and/or install them for ck as well.