Does it really matter any more whether a new release of Xen requires hardware virtualization support? Doesn't all the current hardware where people want to run Xen have such support already? This seems akin to compilers supporting funny x86 memory models long after everybody already had a 386. (There were lots of 286s still around, but their owners weren't buying new software.) How many of these 500,000 servers running Xen can't run KVM? And aren't those on a schedule to be retired, for other reasons (e.g. power consumption, increasing failure rate, etc.) soon?