The only actual Russian-majority area of the country is Crimea, and that has been annexed. You could talk of "Russian-majority" areas, but they, still, have Ukrainian majorities.
Well, Donetsk/Luhansk areas are fully Russian-speaking, and most of South-East regions to some degree.
Being Russian speaking doesn't make you Russian, especially not in Ukraine, Belarus and the Baltics.
In Baltics, there is clear difference between Russians and Estonians, Latvians, Lithuanians. In Ukraine, it's hard to see difference between russians and russian-speaking east ukrainians. But, as ukrainian language is becoming more and more core part of ukrainian identity, i would argue that russian-speaking ukrainians are more Russians than Ukrainians.
