I don't think there will ever be a Minsc Romance, because Minsc simply can't comprehend that sort of thing. His behavior is that of a small child with no idea of what is or is not sexually appropriate conduct--consider his "salve" banter in ToB. Aerie doesn't take the request personally because she knows that Minsc didn't really mean anything bad by it; he just doesn't know. And it's a good thing that the PC understands this as well, because if anyone else (Edwin, say) had made the same speech to *my* Romance, they'd be dead in 3 seconds flat. I suppose you could make a Minsc Romance where you educate him in the ways of love, but you'd have to go all the way down to Minsc's level, and that's way too much like pedophilia for me. I'm more comfortable with the concept of the Imoen Romance.
I also think a Valygar Romance would be unlikely, since he considers his bloodline to be cursed and wants to ensure that the family ends with him. Kinda tough to Romance a guy who's taken a vow of celibacy, although platonic snugglebunnies are OK too. But then again, if you're going to take the trouble of writing a Valygar Romance, you might as well edit him to be willing to have kids after Lavok has been taken care of. But he still shouldn't Romance any spellcasting classes.
There will *NEVER* be a Jan Romance, since that would mean a TOTAL re-write of the Lissa/Hidden quest. Hey, wait a minute....
