The next in line to the Georgian presidency is Nino Burjanadze, she shares the pro-Western, anti-Russian sentiment of the rest of the Georgian political caste and is quite the political oppurtunist, (well, I assume she is, she is the kind to
start a party named after herself).
So forget any idea of the the Ossetian War being butterflied away, if anything, it'll start earlier.
Georgia is much weaker militarily at this point, but on the other hand, we now have a hyper-hawkish POTUS who is perhaps after revenge for the death of his friend and former president... its possible that Georgia could get the American support they so desired during the recent conflict.
Russia's relations with the West will collapse, the European gas pipelines will be shut down and Moscow will give Serbia free reign to do as it likes, (martial intervention to keep Montenegro and Kosovo from seceding - we're looking at a real Balkan flare-up).
There'll be a lot of brinksmanship, but I don't think it'll come to nuclear war. Cooler heads will prevail but the world will be much worse for everyone.