<p>I was checking out Intel's "whatif" site and their Transactional Memory compiler (each thread has to make atomic commits or rollback the system's memory, like a Database would). </p>

<p>It seems like a promising way to replace locks and mutexes but I can't find many testimonials. Does anyone here have any input?</p>

In some cases I can see this as being useful and even necessary.
However, even if the processor has special instructions that make this process easier there is still a large overhead compared to a mutex or semaphore.  Depending on how it's implemented it may also impact realtime performance (have to either stop interrupts, or prevent them from writing into your shared areas).
My expectation is that if this was implemented, it would only be needed for portions of a given memory space, though, and so the impact could be limited.
-Adam