Ksplice and CentOS

I think you're confusing something here. Red Hat provides the full SRPMs necessary to build any package they ship. That fully complies with the GPL's requirements, which are basically saying that you must ship the Makefiles (or the scripts that generate the Makefiles... or the scripts that generate the scripts that generate the Makefiles... or the scripts that generate the scripts that generate the scripts...).

What the CentOS folks are complaining about is that simply having a bunch of SRPMs does not make it particularly easy to build them all in the right order and to install them correctly to bootstrap a working OS image comprised of all those individual GPLed components. Requiring that would be similar to requiring that you provide the rsync scripts you use to mirror ftp.gnu.org so that end-users of your mirror can recreate it.