Let me begin by saying that as of this writing, we don't know for sure when the patch will actually drop. What we do know, however, is that the build that's on the PTR right now is flagged as a possible release candidate build, meaning it could be the final build of the patch. That usually means the release of the patch is imminent. It may not happen this week or next (we can sometimes go through several "release candidate" builds before Blizzard finally drops the thing), but my guess is that it totally will.
So when the patch does hit, whenever that may be, what are you going to do first? You know, besides go hunting for warlocks to stuff and mount on your wall? I find it's good to have a plan when new content drops. Otherwise, I just end up only hunting warlocks, which -- while awesome -- doesn't really involve any of the new content.
So what to do? Fear not, I've compiled a handy list of the new features that apply directly to mages so you'll have something to channel your arcane energies toward once all the warlocks are dead.