The Russians have amassed troops in their own country next to the border of a country with a civil war? They obviously want to start WW3!
What do they gain from Eastern Ukraine? Think about it. Some charred soil, a few coal mines and factories? They're not exactly short of any of those things. Nor are they idiots, the cost-benefit analysis isn't positive. Crimea was a fundamentally different proposition - it was their only Black Sea port.
The power to Crimea from Ukraine was cut earlier this year after some people blew up the transmission lines. Russia claims they have discovered more plots to disrupt infrastructure in Crimea. What's more Russia is bombing in Syria and supporting Iranian operations in the country against the wishes of NATO countries. NATO members have been clear that they may take Kaliningrad in retaliation for any further aggression and have escalated exercises in surrounding countries. It doesn't take a genius to work out that Russia is making clear what their own retaliation would be if NATO makes any aggressive moves.
It's all just a dance, don't expect anything big to happen.