Yeah, there was ALOT. Moonraker, Scientists, Janus Marines (My players of choice), Russians...just, way too many to even count.
Edit: Just an FYI as I just looked it up, with Gameshark characters included (characters you could ONLY get with a gameshark), There's a total of 64 characters in multiplayer. That's an incredibly insane amount to have the development team putting together.