I'm going to post some sample photos from my shoots today. This lens is amazing. I can see why it costs near $2,000. The only disad is that it doesn't do macro. However, it is amazingly sharp all across the zoom range, and the bokeh at f/2.8 is beautiful. I haven't hit the point of lens diffraction, but I had no problems shooting at f/11.
In other news, if you don't have the 50mm f/1.8 for your Canon camera, then get that lens right now. It is dirt cheap (relatively speaking), and is one of the sharpest primes Canon puts out right now. Pros use this lens for headshots.
Samples of 50mm at HUGE focal lengths:
Samples of 70-200mm L (at huge zoom lengths):