Computer Architecture Letters & TC
In my list of fast turnaround architecture-related journals, I should have mentioned Computer Architecture Letters. Four-page letters, acceptance rate currently 22%, an official IEEE Computer Society journal, a breathtakingly strong editorial board, and good papers.
It's also worth mentioning, for those of you in quantum computing, that IEEE Transactions on Computers now has Todd Brun on its editorial board; I think this makes it the first journal with a significant architecture component (though not focus) to have someone strong in quantum computing on board. Todd also seems to be very conscientious about getting papers reviewed in a timely fashion.