I strongly prefer hardware-assisted virtualization wherever possible. I'd like to see more super lightweight OSes like MirageOS, as well as sane trusted computing functionality all the way up the stack, but that might be asking for a bit much.
I'll check out MirageOS, I've also heard some interesting things around CoreOS, which I'm hoping to get some lab time for soon. Finding time to review everything properly is difficult, this article was the summary of 6 months work and 18 hours writing.