The start of the transitioning of the CMS's framework to use threads is foreseen for 2013. This is the reason why an exploration of the different possibilities in which the CMS framework can be parallelised has been schedulef for 2012.
It is at the moment clear that task queue based systems can be used for a parallel version of CMS's framework. Indeed the technology scales well, the transition to thread safe code can happen one module at a time and no thread primitive is exposed to the physicists. On the other hand, the limiting factor of the concurrency is represented by the dependencies among algorithms.
Different technologies have been or are being investigated, like libdispatch, TBB or OpenMP. This last has been ruled out. For example, the API of OpenMP was judged too hard to be used and no 'task notification' mechanism is available.