If you've ever read George Weigel's biography of John Paul the Great, you know that he made attempts but was, ultimately, unsuccessful in reaching out to the Russian Orthodox Patriarch, Alexei II. Part of this had to do with the Russian Orthodox occupation by the Soviets. When they were freed from that burden, there was a natural desire to get people back to church not watch the Catholics sweep in and steal everyone. Of course, it's more complicated than that too complete with, with the little that I understand it, a bit of a power struggle in the Orthodox church between Moscow and Istanbul.
I would never have thought, therefore, that Alexei would see the return of the Latin Mass as a great sign of hope for reunification...never until I read this article that is.