There is a possibility that the current escalation represents bluffing by one of the sides. I've recently seen rumors about international negotiations over Syria. People bluff during negotiations. There's also a possibility that this is the start of an enormous meat grinder that will change the map of the Ukraine for the foreseeable future.
It's unclear to me which side is taking the initiative. Novorossiyan authorities have warned local civilians that the junta may attempt air strikes. I was surprised by that. The junta used aviation in the summer of last year, but then Russia supplied anti-aircraft weapons to the rebels. The junta's aircraft started dropping out of the sky and were eventually grounded.
The junta's front line positions are now being reinforced. People on the ground are reporting massive troop movements. And according to Alexander Zhuchkovsky Russia recently sent additional "military supply store workers" to the people's republics. He says that there are more of them there now than there were during the winter campaign. However they weren't used then. They were there simply as insurance against the possibility that the Novorossiyan Armed Forces would break. They were used last summer, but briefly and only as the last resort.
Zhuchkovsky wrote that he expects the worst fighting to be in the south. If another round does happen, I don't know who'll win it. It's really a proxy war between Russia and NATO and both sides are using tiny fractions of their potential. What determines which side will use 0.05% and which will use 0.1%? Geopolitics and who knows what else? It's certainly not anything that I can predict.