Update:
We are currently in preliminary trials which involve just making a dretch, a granger, an overmind and an egg for the aliens (with alien resources; evos and biomass) and a telenode, a reactor, a scout squad (assault rifle), a construction squad for the humans (with human resources; credits and power). This will be made in Spring and is predicted to take a week or so. We'll be 'borrowing' code from some open source games that use Spring so it should be relatively bug free.
Also, we are working on modding the actual Spring engine to tailor it specifically for our game so one doesn't need to install Spring to play; the parser will be built into the single installer and be specific for Tremulous RTS only. This will make it look and feel more professional as well as making it easier from the programmer's point of view for security. However, this will be midway through the actual build as it will be quite a big undertaking.
For now we are working on the preliminary trials. We are sure to keep you updated.
All Tremulous models are, as far as I can tell, vertex animated but I would like skeletal animation since I think Spring prefers it and it makes it easier for physics, ingame animation etc. therefore if anyone knows where I may find models of a dretch, a granger, a human, a rifle and a construction kit that are rigged up with a skeleton please let me know. Till then I will just have to stick with the buildings.
Also, thank you Demolution for the link to the IRC feed. Didn't think of that!

When preliminary trials get going we will move ahead and contact them.