According to Russkaya Vesna (source here), the morale of the Ukrainian troops is at an all time low. They're not allowed to get out of the shit to go blow off any steam, they're drinking heavily, and they aren't allowed to talk to their friends or family via internet or mobile devices. There may be quite a bit of a stir in the following weeks and I doubt the Ukrainian government wants their own Alexander Sotkin, who through his Instagram inadvertently posted proof of Russian involvement in Ukraine when he posted pictures that contained EXIF data placing him within Ukrainian borders.
Young Ukrainian soldiers are already deserting in droves, despite the fact the government passed a law subjecting deserters to summary execution, among other punishments such as arrest for drinking alcohol or insubordination. This is not a war that Ukrainians want to be fighting, at large. Earlier estimates this year (source) placed desertion estimates in combat zones at roughly 30%, while noting that only a third of the military even wants to be there or for there to be this war. Up to 10,000 young men are hiding in Lviv alone, let alone the rest of the country. The government has even had to increase the age of draftees from 40 years old to 57, because there aren't any young men left to die.
The Donetsk People's Republic and the Lugansk People's Republic have also successfully tested an SD-07 "Dragon" thermobaric weapon, with footage uploaded to VKontakte, the Russian equivalent of Facebook. Thermobaric weapons rely on the oxygen in the air for combustion, thus eliminating the need for an oxidizer in the actual explosive component, leaving the warhead more room for explosives. The blast from an FAE (fuel-air-explosive) causes a pulverizing pressure wave as a large volume of air ignites, and subsequently rapidly expands. Immediately following this rapid expansion, the area becomes a vacuum, allowing air to come rushing back in. The combination of the pressure wave and vacuum lead to ruptured lungs and burst eardrums, not to mention inhaled burning fuel, and toxic byproducts.
Use of thermobaric weaponry means this summer is going to produce footage that makes the battle for the Donetsk airport look like a cakewalk.
We also know that Russia is amassing troops near Rostov and Belgorod, with a massive amount of firepower being sent to Rostov in the last week. The country is already hopelessly divided, and this map may put some things into perspective.
A buddy of mine in the military, who has been following this conflict, put in his two cents, saying it's very likely this summer that Russia is going to make a push for a land bridge to Crimea. This makes sense, as far as the troop positioning is concerned: flank from the north, to draw forces away from the south. They'll have plenty of support from the local populace, who are largely ethnic Russians who speak Russian, leaving the south open to an invasion. The push will likely lead to a battle for control of Mariupol before continuing to the Dnieper. The river would make a good spot for a demarcation line.
Putin has already shown that Obama can't handle playing hardball with him in Syria, and Crimea only served to reinforce it. Ukraine isn't a member of NATO (which, it had a bid for membership, but that got shelved a few years ago amid the election, which wound up being part of the cause of the Euromaidan Square unrest) so a flat out invasion wouldn't necessarily mean going to war with all of the western world. He already knows that Obama doesn't have the stones to put him in his place, and he has the rest of Europe running scared.
There will be a lot more fighting, a lot more death, and a lot more footage coming out of Ukraine this summer. Morale is already low, and losing more cities will only contribute to the domino effect.
