and (hopefully) any libguestfs program, guestfish, virt tool etc will just work as normal. As well as the absolute latest libguestfs you’ll also need libvirt ≥ 0.9.13 and a recent qemu.
What’s the point of this change? There are a couple of advantages. Firstly libvirt confines guests using sVirt mandatory access control (using SELinux or AppArmor). This will [it's not working right now] provide additional defences against rogue disk images subverting the appliance or qemu.
Secondly libvirt already does disk hotplugging, and it will allow us to add this easily to libguestfs.