Very nice.
Although some of the animation is rather jerky and some of the art is a bit hurried, it's obvious that a lot of effort was put into this. I assume that you've learned your lesson about not putting the credits 1/4th of the way into the animation by now, so I'll move on. :P
I have no idea who did the voices (I don't really watch THAT much Star Trek...), but everything fitted in pretty well and the song went quite well with the video as well.
As I said, the only bad part was that some of the animation was somewhat jerky and unpolished. I think you should really think about a different art style, or at least find a quicker way to do this one than tracing bitmaps. There's probably some kind of effect that you can use in graphical programs to make actual faces look like cartoons, or at least you could find something that would help you quicken the process. Try downloading Paint.NET and tinker around with it - it's a simpler, free program like Photoshop.
There's actually an animated movie coming out soon called "A Scanner Darkly" that uses graphics rather similar to yours - perhaps you could see what programs they used for it and see if you can afford them.
Well, that's all I got - I hope it was some help at least. :P
Good luck on your future efforts!