> Is it possible to use AoE as a root-device (like nfs-root) ?
Yes it is possible with appropriate initrd. You shoud be garantie the
root aoe device presnece in the system before you pivote_root to that.
> Another interesting scenario for AoE-root would be running XEN-guests with that (live migration etc....)
It is also possible but it wasn't so stable while I tested.