I only see 2 possibilities for Ukraine.
1. A whole Ukriane (without Crimea) full of only ethnic Ukrainians since all the ethnic-Russian Ukrainians will be living in Russia.
2. A smaller Ukraine (without NovoRossiya).

The extreme anti-Russian violence of the new government and Poroshenko has created too much hate and distrust. Imo, nothing can ever fix that and it will never be forgotten. So if Ukrainians and Russians try to live together after all the violence then it will just lead to new revolutions. With that much violence in only 25 years, can you imagine what can happen in 50.