What is Pixel Shift, and what is its usefulness on the XL2?

Pixel Shift is a Panasonic technology that's been around for awhile. The green CCD is physically offset in the horizontal axis by one half pixel. The process creates more sampling points per pixel and delivers better low light performance, reduced vertical smears, and a wider dynamic range. For more details see http://consumer.usa.canon.com/ir/controller?act=ModelFeaturesAct&fcategoryid=114&modelid=7471.

Thanks Chris!

I'm sorry guys but if you offset the green ccd to, say the right, don't you get a loss of pixels on the left side? how would that be compensated and how does that create a wider dynamic range?

The offset is one-half the width of a pixel. You can't even see that.