I come as an ambassador from the recently beta-launched Language Learning site, where we are still in the early in the trying to nail down some on-topic guidelines.
Strictly speaking, our sites' scopes don't overlap, as Linguistics prohibits questions about advice or help learning a foreign language, and Language Learning is about the techniques of language acquisition.
However, there is bound to be some amount of overlap, and perhaps more importantly, there may be some questions that fall in a crack between the two scopes.
Although I didn't follow it closely, I understand that at the launch of the ELL site, a number of "basic" English questions which were previously asked on EL&U, found much more love on ELL.
Similarly, are there questions you receive which might make more sense on Language Learning? Are there "grey area" questions that you've accepted, perhaps grudgingly, but might receive better attention elsewhere?
If such questions do or have existed, I'd love to know, then Language Learning can decide to what extent we would be equipped to handle such questions.