I was very happy to get my question answered by the nice people that run TES:O's site.
I wrote, "I'm a mer at heart, and my favorite race of Elves is the Falmer (Snow Elves). I was intrigued by their appearance in TES V: Dawnguard and would like to know: will we learn anything more about their race, history, or culture in ESO?"

They answered, "In the Second Era, the Snow Elves are a near-forgotten legend, and the fact that they’ve degenerated underground into the feral Falmer of Skyrim is a deep secret. But secrets can be discovered, and the Falmer may make a future appearance in ESO."

The whole thread is here: http://elderscrollsonline.com/en/news/post/2013/02/22/ask-us-anything-variety-pack-2

I'm really liking these AMAs, I always learn interesting things about online or TES in general.