I think Russia is just trying to suss out the world's reaction and see who moves and how. If no one does anything significant in response, they will stage an attack some time in the near future. It really doesn't benefit them to start a war over Ukraine, so if they think a war will come because of it, they will just say it is the world overreacting and they are just running exercises.
If the world has no real response, then they will do just as they did with Crimea and get away with an invasion with little to no effort. The only thing is how much Ukraine is prepared to battle with Russia on this. Many Ukrainians are tired of a government that does nothing for the people and is typically always extremely corrupt, mixed with their lives being in the dumps, I don't know that it really matters as much to an average Ukrainian trying to get by in life, in the grand scheme of things.