This is one of those places, where it is all speculation.
Even if litecoin was working with f-c-book, it could all fall apart before the integration.

And since I really do not care for f-c-book, I would be conflicted if they did get together.

I believe that we will see a meteoric rise in litecoin. Just because its like bitcoin, well known enough and has formed a bull flag. With any really good news, then it will just be a more spectacular rise.