I know this is for 2 players, but is there anything that would prevent multi-player from working?

There are cards that are worded as if they are designed for more than 2 players. I would guess that they plan on releasing "multi-player" rules after, or when, the game releases.

The cards are phrased with "target opponent" or "each opponent" so there is most likely a multiplayer aspect coming at some point. Although there isn't one announced now, I am willing to bet, based on the way cards are written, that its going to happen.

A free-for-all mode might be fun. It wouldn't be very thematic, but neither is having Ren and Dooku team up, so I say the more the merrier!