I feel you on the D&D-only vibe. My co-GM and I switch off running 'big' games while the other does short side games from time to time. Usually we manage to squeeze in non-fantasy in the side game slots...but the main game is always D&D. It gets really tiresome sometimes. Switching back and forth really helps though - as does our GM-only game, which lets us play stuff our players would never try...or would try to overpower (I'm running a Star Wars Legacy game for them where they're both playing Jedi...something ripe for abuse).

Honestly not sure which version of Deadlands we're playing (I look over someone else's shoulder since I don't have my own book. It's an early version, I think (i.e. not GURPS, not D20). Stats were determined by cards, etc.
M