I suspect that all Russia really wants is what they've always wanted... a warm water port. Anything else is just macho posturing. They want Ukraine because they want the Crimea. They want the Crimea because they want Sevastapol. But give it a few more years of global warming, and they should have plenty of warm water ports.
I won't be surprised if Russia invades Ukraine that has been there long term desire, but on the other hand it may not be that easy because of the magnitude of repel America will throw at them.