Russia + Georgia = ?

I’ve been paying attention to the Russia/Georgia/South Ossetia war that’s going on and I’m trying to figure out (from my Oh So Worldly knowledge) what Russia’s angle is here.

Obviously you don’t go committing a division of troops without a good reason. I don’t know enough about the Republic of Georgia to understand what it is about the area that makes Russia want to either destabilize it or force a regime change (or to split of South Ossentia). Are they looking for weaker states on their borders to force them into economic satellite-hood? I’d think, just given their geography, that they already were. I’m assuming that Russia is Georgia’s majority trading partner, unless it’s Turkey. I really don’t know. I also assume that there’s no reason that Russia would want to conquer Georgia from a geographic standpoint. They’d acquire a couple Black Sea ports, a mountain range and a valley. I’m guessing that this is all political (which Clausewitz would say is the whole point of war).

Anyone have any knowledge or thoughts?