One thing you don't need to worry much about is the megapixels. From what I've learned 99% of us don't need anything higher than 5.0MP. 5.0MP is excellent quality print all the way up to 8x11. So spending gobs extra on the 11 when they have an identical 7 is not worth it unless you are a professional. At least it seems all the new 10MP are as cheap as the 5's used to be.

The single most important feature for what us hobbyists need in a PAS would be a high quality MACRO. Next would be a quality lens. The glass can be what makes or breaks a good camera.