This is about an old article posted in MSDN Magazine but I want to make sure you didn't miss the paragraphs about System.Transactions that Don put together in "A Guide to Developing and Running Connected Systems with Indigo":
“Indigo also provides significant support for transactional programming. Indigo-enabled versions of Windows support a service-based transaction manager that may be accessed via the System.Transactions framework or the WS-AtomicTransactions protocol. The new System.Transactions framework makes transactional programming simple and efficient throughout the platform (it supports
System.Transactions provides a new in-memory transaction manager that allows volatile transactions (that is, transactions that do not involve durable resources) to commit or roll back efficiently without incurring any disk I/O. To support durability, the in-memory transaction manager will transparently promote volatile transactions to durable transactions by coordinating through a disk-based transaction manager like the DTC the moment a durable resource manager enlists itself with a transaction.
System.Transactions defines a simple managed interface for writing both volatile and durable resource managers. System.Transactions also supports any resource manager that can speak either OLE transactions or the broadly adopted WS-AtomicTransaction protocol. To enable efficient transacted access to the file system, the Longhorn version of System.Transactions directly supports both the Kernel Transaction Manager (KTM) and the Transactional NTFS (TxNTFS).”