Just fyi, if anyone is interested in an NFSv4 client for Mac OS X 10.4,
can anonymous ftp:
cd pub/nfsv4/darwin-port
get xnu-client.tar.gz

You will need to accept the terms of the APSL and download kernel
sources from Apple, in order to set it up and use it. It does include
support for Kerberized NFS (and v2, v3 as well as v4).

Just in case you are interested in it, rick