Far too comprehensive, even for an expansion, would be a full new game really - or they may as well make a whole new game at any rate.
This is probably the case. I get the impression that just redoing the voice acting alone for different genders and princes would be really expensive. Not exactly what the realm of $5-$10 DLC could pay for.
Plus,can you imagine the flak Larian would get if they tried to sell a second gender as DLC? Probably a lot.
