I always wanted to add cyrillic support to my fonts but never got my head around it, guess this might be a great time to start then :)
The software I use to build the fonts lists the following 33 character pairs for the Russian Cyrillic:
Аа Бб Вв Гг Дд Ее Ëë Жж Зз Ии Йй Кк Лл Мм Нн Оо Пп Рр Сс Тт Уу Фф Хх Цц Чч Шш Щщ Ъъ Ыы Ьь Ээ Юю Яя
I'm now in the process of drawing those into the Mood fonts. Are there any other characters you'd like to see?