A MSNBC article on the fighting in the former Soviet Republic of Georgia notes an interesting fact that could account for the Georgian government launching its offense the day of the Olympic opening ceremony:
He also speculated the timing of the attack, hours before the opening ceremony in Beijing, could be a signal from the Georgian government. The Russian resort region of Sochi, just miles from the border of Georgia's other separatist region of Abkhazia, will host the 2014 Winter Games. "It might be a signal to the Russians saying that the Sochi Olympics will not go the way Russia wants if there is no progress on the settlement in Abkhazia," Popescu said. Besides being important to Georgia as a matter of national pride, Abkhazia also includes more than half of Georgia's Black Sea coast and is believed to have significant oil reserves.
The article also notes that Kosovo's declaration of independence from Serbia earlier this could have sparked additional tension:
Tensions rose markedly this year after South Ossetia basked in Kosovo's declaration of independence from Serbia, calling it an international precedent that legitimized its own refusal to remain part of Georgia.
South Ossetia’s backer, Russia does not recognize Kosovo's independence but consistency is not needed in international politics.