Guy Harris was referring to a client bug in Soalris 2 where the files are deleted on the last close of the client.
All correct clients delete the .nfsXXXX turds on last close.
The cron job cleans up .nfsXXXX turds left over from clients that may have *crashed* while holding "open-but-deleted" files. The clients keep no state over reboot to clean these things out (they could, but why bother...) Most servers clean out old files.
For our box, a cron job run on the admin client would be appropriate to clean out old .nfsXXXX's left from crashing clients...
I don't think that it is a bug as such. .nfs files are created when an open file is deleted, this is an old trick for creating temporary files, they are automatically deleted when the program exits, however it exits. Basically it's a way of adding state to a stateless system. I am not sure if the nfs client ever tries to delete those file, I would guess that it attempts to but definitely doesn't always succeed so there is a cron job on all nfs filers I have seen that cleans up old .nfs files, typically something like:
find / -name .nfs* -mtime +7 -exec rm -f {} ; -o -fstype nfs -prune