I am shooting a spoof on the Apple/PC commercial and am trying to get as close as possible "The Look" of the commercial, have the actors and a white background, shooting with my XL2...any tips?

Really what you see with those commecials is what you get. It's a matter of just running through standard operating procedure as you would on any other shoot. I would simply recommend doing tests and trying different in-camera settings to achieve the look you want in terms of coloration, value, etc, then dedicating that to a camera preset. Also, obvious but important. White balance.

is it just me or does the shutter speed seem high on these ads? would that contribute to the overall clarity and "whiteness" factor?

-jonathan