I think (well, believe) that it is not that bad as it was in Vietnam. It was said several times here, in Russia, that US and Russian military established a communication link to prevent accidents in the airspace. Hope it will work.
The fact that US and Russia support different groups of "bad guys" is sad, but actually nothing new, and serious people do not take it as a considerable escalation. Just a couple of extra sorties to destroy these newly supplied weapons if they are used not against ISIS, Nusra front and likes.
I still wonder why not to jointly (i.e. US and "their" rebels on one side and Russia + Syrian governmental forces on the other side) vaporize all those totally mad bloody ISIS & Co. maniacs and then jointly decide how to establish an acceptable secular regime in Damascus. As far as I heard, "baby Assad" was ready to study a compromise that would allow his head remain on its place while giving most of the power to a sort of a yet-to-be-defined "democratic" regime (whatever it may mean in that campus). IMHO, personal ambitions on all sides prevent coordinated "taking arms against the sea of troubles".