The Q2PMP has posted a message from Raven's Brian Shubat regarding the interchangability of Quake III: Arena and Star Trek: Voyager - Elite Force player models in deathmatch (originally posted to Raven's Forums). Here's what he had to say:

We are going to attempt that Q3A and Star Trek models be interchangeable and compatible between each program. That is to say when it comes to multiplayer deathmatch there shouldn't be a problem. Single player is a different matter altogether and Voyager will require many additional animations from Q3A models.