So here are my replacement movies and pics for six of the GC2 Alien species.
Preview:

Download:
http://www.megaupload.com/?d=A0XD6BV2
(over 70mb zip)...I found the upload was quite slow, maybe I can find a better host. For now this should do it....
Installation:
I guess it's best to put the files in a mod subfolder so original files don't get overwritten. Unzipping the downloaded file should produce two subfolders called "Movies" and "Race".
1. Movies
These are .bik movies for the negotiation and UP screens. Please copy to Your GC2Main Folder\Mods\Your Mod\Movies
2. Race
These are pics for the Alien selection during game setup, also used in game as stills. They go into Your GC2Main Folder\Mods\Your Mod\Gfx\Race
If you follow this procedure and specify the mod folder where you installed those files in the game options under "Current Mods Directory" those files will replace the original gfx and movies of the Drengin, Arceans, Korx, Iconians, Thalans and Drath in your next game. However, with a little xml modding you can use those gfx for any race you prefer.
All those are of course free to use for any other mod, as long as it's no-profit. Just a little art credit would be nice. As would be any feedback, be it positive or negative.