I think a move into Eastern Ukraine is more likely than not. By no means is it certain, but I think it's likely. After Crimea, the remainder of Ukraine is gravitating towards the EU and NATO for support and protection.
In my mind Russia has two options: address this now, while Ukraine is still a mess, or fight a covert proxy war with NATO with the aim of destabilizing Ukraine and getting it back into the Russian sphere of influence. The latter seems risky and if it proves unsuccessful it may still lead to a full scale military operation at a later time.
It ultimately boils down to risks and costs. What are the risks and costs of 'liberating' Eastern Ukraine today vs. it becoming a NATO outpost tomorrow?
Lastly: during the last few days of the Sochi Olympics, right before the stealth invasion of Crimea, there was an increasing stream of video snippets (mostly cell phone video or cash dashcam) from Russia showing columns of trucks and APCs. In the last few days similar videos have surfaced, supposedly from the border region with Ukraine. This time the videos are showing tanks, artillery and other heavy metal. This may well be false information, I have no way of verifying its accuracy. But all signs that I see show that trouble is brewing - hence I am on guard. Maybe everything will blow over, I'd certainly hope so.