Normally I would be very opposed to the idea of having Jill and Leon together as the main characters, simply because I don't like either of them very much and there's no one else to fall back on if they're the only options. However, now that I think of it, it could actually be interesting to see how they work together and interact with each other. They have a few similarities in some regards, but are also very different in others.
For example, I wonder how Jill would react to being hit on by Leon, something that is not at all the kind of treatment she's used to from her male partners (except Carlos). Perhaps in the middle of the story, they could become very desperate and start a drinking game by a fire, with a heartbroken Leon telling Jill about Ada, the only woman who doesn't reciprocate his affections in the way he'd like her to and is therefore the reason for him hitting on everyone else, and Jill telling Leon about Chris, her long-term partner who won't love her back either unless she undergoes a sex change and renames herself to Piers. In the end they decide to drop the mission and their crushes and elope with each other instead. Wouldn't that be nice?
(The part with the drinking game and everything after that is obviously not to be taken too seriously, but I would still be interested in seeing how that partnership would work out.)
As to who I'd really like to see, I'm relatively indifferent at this point. We just had a game featuring Chris, Ada, Jake and Sherry, who are some of my favourites, and Claire will be back in about a week. (Yes, people, it's only one more week until the first Revelations 2 episode!) So for now I'm pretty pleased with the character appearances, they could go in any direction from here.