I am actually a moderator for http://russian.stackexchange.com and today I was kinda surprised to find a second Russian-language dedicated beta which I have no idea to exist - http://rus.stackexchange.com.
There are two reasons for me being surprised. First, if you search area51 by word "Русский" ("Russian") you won't find nothing. If you will search by word rus you won't find Rus SE as well, only Russian SE.
Second, the only difference between Russian and Rus is that on Russian SE questions are asked - as well as answers are given - in both Russian and English, as opposed to Rus SE which is sort of Russian only.
To my experience all language dedicated SE sites are bilingual by and that is, in my opinion is benificial for everyone. On the other hand, I need to acknowledge that the amount of users using Rus is impressive.
Rus Russian
===== =======
questions 7911 1,402
answers 17,290 3,964
answered 95% 100%
users 3,300 4,207
visitors/day 9,943 763
It looks like that if will merge this two very closely related stack into one it would be very good for Russian language dedicated community. It looks like it we would be way closer to getting out of beta.
UPDATE: I should note that Russian SE is not an analogue of ELL - it's exact analogue of English SE or French SE. This is crucial. One can take literally any question from Rus SE and it will be 100% relevant on Russian. User @m0nhawk is just wrong in his assumption.