World War III is not imminent. Although Russia has been making a lot of noise and threats, ultimately, its leaders will not take the self destructive step and start World War III. Putin is pragmatic, and he gets political points at home by sounding strong and turning the public's attention away from Russia's economic trouble.
No, World War III is not going to happen anytime soon. Hopefully, there will never be another World War, but the Russians seem to have a hand in every conflict happening in the world. World War III is not looming, but we are in a major time of conflict in the world.
I don't think Russia wants a full-on war. When Trump becomes President, Putin is going to be happy and a bit more cooperative so I think the tensions in Syria will ease. That may not be the case if Hillary wins, but I don't see how she can anymore, so a third world war is out of the question.
While the state of the world is currently on shaky ground, I do not think World War III is imminent. Russia has delayed peace talks with Syria, but I think this is just a delay. I do not think an all out war is going to ensue. Russia is just using this to get the attacks to stop.