So now everyone awaits Obamas mission to Moscow on the 6th of july. Most analysts think that his performance would mean the difference of "invade" or "not invade" Georgia. I really hope Obama will be firm, and won't proceed with the naïve "reset" project. Russia needs US as an enemy in order to keep the current cleptocracy at the power, thus persuing the "reset" project will only serve to project US as weak, and confirm the image Putin want's to create.
The rest of the discussion and comments suggest that Russia has enough conflict in the North Caucasus to want to have more in the South.
On the other hand, in the 19th century, Russia conquered the North Caucasus only when it had conquered and created a stable peace in Georgia and control of its southern border. So trouble erupting on its southern border would need to be sorted out first, with this line of thinking.