We can make this feature (passing O_DENY* flags received from clients to filesystem) can be turned on/off on Samba/NFS server to let this particular use case work. In general, I think we really need to be sure that nobody has a read access for files that a Windows process opened with O_DENYREAD (because there can be important reasons for the Windows process to do so).
It should only affect windows emulated tasks, nothing else. If you want to do locking friendly behaviour you could also take lockf locks so that Linux domain code that *wishes* to be nice in this area behaves the way you want.
Without that you break so much stuff its a horrible idea (eg backups, ubuntu one sync etc).
Alan