Is there any possibility that other foreign nations may get involved?
No. The US is tied down in Iraq and has diplomatic worries abroad (but the US supports Georgia diplomatically, for sure). I doubt any European country would want to intervene directly against Russia. Ukraine, depsite Yushchenko being close to Saakashvili, will certainly not intervene, because Russia is a threatening power to Ukraine. I'm not sure what Putin's Belorussian clone is doing in this situation.
Essentially the only powers I could see getting involved are Azerbajian, Turkey(if Adjara revolts) and perhaps Armenia.
For real I think that no one not directly threatened by a direct involvement in the conflict would move until US say what they do. I would be surprised that US intervene too, but NATO rethoric is the totally opposite of the Russia one. Russia says: "Ossetia is no more part of Georgia" and NATO says: "The sovereignty of Georgia must be respected". Diplomacy can still rule the conflict but the ways to do so are tiny.