Cset 15383 from xen-3.1-testing.hg moves nvram files from /usr/lib/xen/boot/ to /var/lib/xen/nvram/ to accomodate for a read-only /usr. This change is recommended for inclusion in RHEL 5.2.
If we move the NVRAM files, then when any existing user upgrades from 5.1 to 5.2 they loose their persistent VM state. While I agree it makes sense for FHS compliance, moving files around in this way is not the sort of change we can slip into an update. IMHO, this is dev-NACK.
Closing as WONTFIX.