Unfortunately, transactional NTFS is being deprecated. MSDN says:
"Microsoft strongly recommends developers utilize alternative means to achieve your application’s needs. Many scenarios that TxF was developed for can be achieved through simpler and more readily available techniques. Furthermore, TxF may not be available in future versions of Microsoft Windows."
Which is a shame, because, conceptually speaking, a true transactional filesystem with snapshot semantics makes some things so much easier.