This is what excited me most too. It is a very similar approach than what we did in a project when we had to add multithreading later on, namely to use tasks an

This is what excited me most too. It is a very similar approach than what we did in a project when we had to add multithreading later on, namely to use tasks and hierarchical queues. But with GCD, it has the knowledge of the number of cores and running threads and processes so it can allocate the whole system's resources much better. The other thing I like is how well it is integrated with other new features like blocks, OpenCL and Clang. I expect to see something similar on Linux soon, or (wishful thinking) if the GCD interface was ported to other unices so we could write portable multicore application in a sane way.