The few Russians I spoke with (in my broken Slovak/Ukrainian) did not seem happy being in Ukraine. All analyses I have read is that the vast majority of Crimeans did not like being part of Ukraine. The Tartars had only 10% and would have preferred to stay in Ukraine.
When I was there, the Ukrainian government was undertaking programs to reduce the importance of Russian in Ukraine. I met one Russian lady from Dnipropetovsk who was going through her Ph.D. program. She had to deliver her thesis in the Ukrainian language--and she thought she was not fluent enough to make that transition. Whether this is right or not (the Soviet government was discouraging all languages other than Russian in its time) is a moot point: such actions tend to build political resentment.
My Ukrainian family lives in Chernivitsi. This western city has about 10% Russian speakers. According to my uncle, and they were agitating against the "Ukrainianization" of their language. Again, my readings back this anecdotal story. The Russian minorities were not happy.
The western media is portraying Ukraine as a fairly unified society. But it is not. There are Russian minorities. There is a lot of neo-Nazi forces. And there are the Ukrainian kleptocrats who have raked billions from their countrymen.
It seems the Russian minorities in the Baltic Republics would NOW prefer to stay as independent countries than occupied by Russia. If Ukraine has build a reasonable democracy after 1991, maybe its Russian minorities might have been content.