I just did a talk titled 'Live Migration of Virtual Machines From The Bottom Up' at the FOSDEM conference in Brussels, Belgium. The slides are available at this location.
The talk introduced the KVM stack (Linux, KVM, QEMU, libvirt) and live migration; introduced ways the higher layers (especially oVirt and OpenStack) use KVM and migration, and what challenges the KVM team faces in working with varying use-cases and new features added to make migration work, and work faster.
There was a video recording, I will post the link to it in a separate post.
Update: video recording available at this location.