On camera IS versus lens OS, there was an excellent article on a quantitative comparison between the two approaches:
Image Stabilization Test: Olympus E-520 SLR Body - SLRgear.com!
The basic outcome was: "The Olympus E-520's IS system turned in a superb performance, very much on par with the best lens-based IS systems we've looked at." In other words, the camera-IS was as good as the lens OS.
Practically, a major, major advantage of the camera IS is the greater, wider range of lenses that you can use. Lens with OS are rarer and dearer.
Lastly, if you choose an OS lens, beware that lens OS and camera IS do nto work well together. You will need to switch off one or the other.
Hope that the comment will help....