We've covered this type of thing before, but Blizzard has a long way to go in making their data open to any players who want to use it. Just recently another MMO named Dungeon Runners decided to break open their player data, into a form that almost anyone could use, and we know that Blizzard has the ability to share lots of data online, but they still haven't opened it up yet. 2.4 is giving us a lot of different ways to view our combat data, and almost every day the Armory adds new features, but none of them have yet been aimed at getting the data out of there and doing cool stuff with it elsewhere.
Maybe the reason for this is that they're planning to do it themselves. At any rate, there is a ton of information on Blizzard's servers that players would love get their hands on, and there are plenty of things on the other end to do with it. All that's required is for Blizzard to give us some hooks in, and then real WoW mashups can begin.