I'm gearing up to run an old republic pen and paper game and would like to use X-Wing in some of the space combat scenarios. Are there currently any plans to release any old republic expansions?

No. Nothing has been announced beyond what's currently available. Furthermore, the core set rulebook says the time frame of the game is the original trilogy.

It is my understanding that FFG only has the rights to the original movies. Just look at the SW games they are putting out. All original movies.

I have seen EU in the card game and edge of the empire so it isn't just movie content but it soo far is all set in the GCW era, no OR or AE yet. Honestly I would imagine bioware has some stake in the OR timeline ATM so it would depend on what the legalities are.

I would love to see a TOR-themed set eventually. The player ships would all make great options, as well as the various fighters and bombers seen in the game. And, it would have the upside of being more interesting to play than TOR's space missions.