You know. When they have more time to do stuff between patches. I think people collectively erased that from memory...
But they really have more time in between patches? I honestly thought that is the busiest, since they have to deliver stuff for the next patch(es) and work on stuff for the next expansion. Truth be told, as much as we got 2-3 extra weeks between patches now, I still feel they deliver new content in a rather decent pace, compared to WoW, for example (sorry, it's the only thing in my experience that I can compare to).