Of course, as a wedding photographer, sharpness is one of the factors to a good photo. Here's an example of how sharp our photos can be. In any photography courses, you will learnt that composite, rule of 1/3, lighting etc are also keys to a good photo. In this instances, I like to focus on my photo quality, sharpness.
Achieving sharp photos must first start with good quality lenses. This is the sole reason why I use high end quality equipment. You cannot make a poor image quality good but you can make a good quality photo poor.
Sharpness can be quite subjective. I don't pixel-peep. Pixel-peep is a term where photographers go into great details (zooming in) into a photo and see how sharp the photos are. With each of my photo, I know where the focus is locked. During my editing process, I do look for overall sharpness of the focused point/plane. Sharpness can be "adding" via post-processing as well. In the near future, I hope I will have the time to give a tutorial on How to sharpen your image with photoshop.
On the other end, you can also have photos that are too sharp. People want to look best in photo. They want to look good with smooth skin complexion. In this case, sharpness have to be smoothen out with post-processing to get rid of bumps and humps. This is generally the case for fashion/modelling photography.
Outliers: There will be photos that sit outside this technicality. Often, movement on dance floor are captured by dragging of shutter speed to create the feel of motion.
Different camera models will have different megapixel. Hence, sizes of photos from different camera will be different. Camera models can contribute to the sharpness of an image but these days, this is often not the case.