Just tried a xen install (i.e. appending 'xen0' to the anaconda command line) with FC6 test1. kernel-xen got installed, but no xen. Sounds like fallout from the fact that the xen dependency got removed from the kernel package
Yeah, it's at least somewhat related. Need to think about what we want to do in the new world/if it's time to be able to sanely expose the Xen package group (which is what I'd really prefer to be honest rather than hacks like this)
Xen option is now visible in Anaconda, and includes all the right packages. This is no longer a bug.