Some new information about the "Citizens of Chernarus" has been revealed on the ArmA2 official web site. Here is a YouTube video thanks to Kenwort.
Citizens of Chernarus
Proud people of Chernarus were divided by the civil war and its consequences. Majority of Chernarussian citizens are of Chernarussian nationality, with their own language and culture. There is also Russian ethnic minority living mainly in the northern territories, where Russian is second official language. People are also divided by their political alignments and sympathies.
alternative link to the video: