For those concerned with improving their mechanics, check out
Day[9] Daily #208. There was a thread today on Team Liquid about study resources, but I can't seem to find it again.
Oh, and macro is far and away more important than anything else in the game. Good macro will get you to Diamond, and assuming you're marginally competent in other areas of the game, great macro will get you to high Diamond. The reason you don't hear the pros talking about it very much is that they've all pretty much hit a ceiling with it, so at their level it makes sense to be thinking mostly about build orders, micro techniques, etc.
Here's something else that might interest some people:
SC2 study group