I've often wished commercial games had splitscreen, especially when you didn't need a keyboard for each player and a joystick or controller would work just fine. However, I don't see it happening with Tremulous, though I think it would be a good idea for the other games. The reason is that splitscreen suits itself well (perhaps not quite as good as a home network, but still) to low player counts and deathmatches. Hiding information isn't that important, so its not too big of an issue if someone looks at your screen. In Tremulous hiding information is critical (if I've run out of cr, how well my base is holding up, etc.). Low playercounts are also somewhat problematic for trem given the nature of managing/defending a base.
So I like the idea, but not for Trem. Unfortunately I also don't have any advice or time to give you as far as coding that goes. However, Good luck
