If it's Back to the Future, then I'll build the DeLorean for you (and that is a serious offer. I love that car...). I built one in LDraw, a few years ago. I've still got the model file. Of course, many of the pieces I used aren't in Blockland, but I'm sure I can fake it. On top of that, chances are that I can make something better in Blockland than I could in LDraw, because of brick stretching, and whatnot. Though, I strongly doubt that it's Back to the Future. Even if it is, I'm not actually sure I'd want to get involved. I'd be worried that the ideas wouldn't be pulled off very well, and that it would end up looking "not so hot," in a manner of speaking.
Honestly, I can see the Matrix being done, but I'd expect some serious video editing to be done if it were to be done right. Personaly, I think you'd be better off re-enacting scenes/episodes from Red vs. Blue, just so you get an idea of what you're doing. Besides, if you do it using Legos, I'm sure you could make some things much funnier than they were originally. Think of Lego Star Wars as an example. I couldn't help but laugh my head off whenever someone died. Not only did they make a funny "Ahheee" sound when they died, but they also left their pieces all over the floor. It was HILARIOUS! So, done right, I'm sure you could add a comedic twist on just about anything. Good luck with it. Mouser X out.