Transactional NTFS
This is something important: NTFS is gaining transaction support.
That would make this possible:
BeginTransaction
Copy *.* OverThere\
CommitTransaction
If your system crashed or the copy was stopped for whatever reason before the CommitTransaction was done, it would all be rolled back.
Transactional NTFS (TxF) has almost zero overhead when not using transactions, and "single digit" overhead when using transactions.
I hope this isn't just a server addition.