My first questions is where are the queen cells located and is your hive eggless or truly queenless? If the cells are on the bottom of frames, and there's a queen who's not laying, your hive is getting ready to swarm. That's a tough one to turn around, but consider reading up on the Demaree (sp?) method for swarm suppression.
If the queen cells are scattered about and you're truly queenless, your hive is superceding. Your hive has already taken control of the situation. I'd just let them go and raise their own queen. You won't lose that much production, and you won't have to deal with the hive not accepting a foreign queen. Plus, as Scott suggested, a cache of queen cells can come in pretty handy this time of year. And it's a whole lot better situation than being queenless without queen cells!