In the latest nfs-utils build (nfs-utils-1.2.0-17.fc12 The following
bugs have been fixed:
- mount -t nfs4 no long works
(https://bugzilla.redhat.com/show_bug.cgi?id=529407)
- Protocol does not roll back when set from configuration file
(https://bugzilla.redhat.com/show_bug.cgi?id=529864)

The second bz has more potential of being painful since mounts to
legacy NFS server that only support UDP will fail.

Also these bug fixed have been upstream reviewed and accepted, which
is not the case with the -16 build (the version in the beta). Also from
these discussions, a fair amount of testing did occur.

Finally the compromise of setting the default version back to version 3
using the /etc/nfsmount.conf file is still in place. There was some talk
about having the mount command automatically rollback to version 3 when
the server returned the ENOENT error (which happens with pre-F-12 Linux
servers).

See http://linux-nfs.org/pipermail/nfsv4/2009-October/011471.html for details.

In the end, I decided not to do this since its not clear how we would interact with
other NFS servers plus it a fix that my not be too easy to back out...

Please consider nfs-utils-1.2.0-17.fc12 for the GA release.
The build: http://koji.fedoraproject.org/koji/buildinfo?buildID=137893