For the Fae, I'd go with them being stuck on Earth for the most part, perhaps as strong as ever, perhaps not. The few that could make the trip through the interstellar void would then go on to found their own Courts, which would tie in to the climate of a new planet in a brand new Nevernever. There's a lot of fun to be had in this because the Fae would need a long time to get their power structure up and running, especially without any stone tables to sacrifice people on. They'd also have to breed new Changelings to make up their numbers, which is a lot slower than most supernatural species need to repopulate themselves.
So we'd see a very different power structure, where the Faerie Courts are among the lesser powers, but with huge growth potential. The vampire courts (Red obviously excluded) would be in prime position to become the big players in the new extra-solar society. The Black Court would find this especially good for them as all they'd need is a single vampire on a ship full of humans turn bring themselves back to pre-Stoker numbers.
As a side note, a while back I came up with an idea for a Dresden Files/Firefly crossover story where the White Court had founded the Companions Guild, Nicodemus was the head of the Alliance and Toot Toot was a Sidhe noble. I should really get around to writing that some time.
