Rasp of Pi, the turret with a Pi at heart

I am thinking of building an automated turret (something like the level 1 turret from Team Fortress 2) using a Raspberry Pi as its processing center, only I am not sure in what direction to head to. So far all the planning has been in my head thinking of what I will need to accomplish this project; I even started a blog to document my journey -- http://raspofpi.blogspot.com/.

This is what I've thought about so far:
* The turret would shoot paintballs, since they are non-lethal but still visibly mark their target.
* Even though it will shoot paintballs, it will not contain a paintball gun. Most parts will be bought at a hardware store. This leads to questions like, how will I build the firing mechanism?
* Most code will be written in C, and if possible, the balistics for the paintball will be in Fortran. I found a PDF of a book that details image processing algorithms in C, which would be used because I am planning on the prototype only scanning for those targets found at shooting ranges and then aiming.
* Camera would need to be low powered, probably black and white to reduce the amount of data produced.

So some of my questions are:
* How well would a Raspberry Pi be able to operate if the image feed was video, that way the turret would accurately hit a moving target?
* What kind of hardware should I be looking for in terms of the camera, the motors to rotate the turret, the firing mechanism, and what will control those 3?

I saw a video of something similar involving squirting water at squirrels on youtube, I think coded in Python.

Any chance you have the link or can post it? I know exactly what you're talking about; it's a TED talk. One of my professors started showing it to us in class last semester but haven't had luck finding the video.

Here's one:
http://www.i-programmer.info/news/105-a ... nd-ai.html

Lots of hits for "python squirrel opencv"

Using a water gun would save you building a paintball gun & be safer!