Thanks for the info! What you are talking about is just a skin, though, not a full model. I really meant to ask if I could add my own models, as in a new 3d model, with new animations, new sounds and new skins.
I'm already familiar with modelling, skinning and animating for Quake 3. After opening up the pk3 file I noticed that the WQ3 models had a few more upper animations than the standard Quake 3 ones. I was wondering if this model setup will be used for the next release as well, because if it's the same, I can start modelling and animating right away.
Otherwise, I'll just wait for the upcoming release.
As for the lack of shaders on your skins, you don't really need shaders. Skins can look good without them, that is, if you paint them well.
I don't think the original WQ3 skins have any shaders, either. They just have nice shading and stuff. Just practice a lot and use dodge and burn for your shading.
You don't even need a shader program to make shaders, btw. You can write them in notepad. Just open up some existing shader script files and look how it's done. Take a look at the alpha channels in the corresponding tga file, too. But like I said, shaders aren't really needed.
If you post some pics of the skins you have made, I can give you some tips, if you want.
It would be cool to see people make custom stuff for the mod and release them for others to download.