I have packaged Russian keyboard using ngrams as distributed at http://ruscorpora.ru/corpora-freq.html . In addition, hunspell dictionary was converted to UTF-8, as needed. Not sure whether its the best ngrams available, but give it a try. If someone gets better frequency distribution, please feel free to suggest improvements.

I think Russian would heavily benefit from proper Unicode support in presage. Right now, Presage doesn't know how to normalize Russian letters (lowercase or otherwise). So, we would love to get an enthusiastic ICU specialist who would have time to work on Unicode support of Presage. I'll be happy to help with the database parts and normalization, but have rather limited time to do it all. In addition, my primary languages work quite well already