It seems as though VGA and PCI passthrough are more mature on Xen, and apparently one no longer needs a nonstandard kernel ( which was a previous objection ). So I'd vote for inclusion: I'm transitioning to a new system with new hardware and would rather stay with Slackware rather than Debian or Mint (not that there's anything wrong with them) but Xen support is sort of a deal breaker at present. I'm not sure I have time to work out all the issues myself.
[edit: ah whatever, I'll give it a shot anyway... I'm sure it'll be hours if fun