Ingar is right, there is quite a difference between standard deathmap maps and maps for a teamplay and tactical based game like Tremulous. You could extend the entire thing to, let's say, 24 hours.
However, I remember another nice project from planetquake.de. A guy called Xian started the project "48 hour mod". In this mod, 12 people contributed with their stuff, like new models, new weapons, new maps and also some new textures. Afterwards, you could clearly see, that everything was inspired by the standard Quake 3 layout, but it was impressive, what they've done in this time. Maybe you could organize something like that?
All in all, quallity takes time. So I won't throw a bunch of bullshit (sorry, but that's a fact for this short amount of time) out to the community.