Saying to a professional photographer "That is a great photo, what kind of camera do you have?" is rather like saying to a cook..."That was a great meal, what kind of oven do you use?" The best and most expensive photography equipment in the world will not make someone a great photographer, however, having high end professional photography gear will certainly help make the quality of the images a lot better.
It is also important to have back up gear, lots and lots of it! Accidents happen and not only might we need to grab one of the back up cameras, we might need to do it in a hurry, so we always keep an extra camera case, just full of our back up photography equipment with us during the wedding ceremony and reception.
Below is a list of our equipment, which seems to be expanding more and more each year. I myself have switched from Canon to the mirrorless system and Sony. Here is link to one of the reasons why
However, as a past "Canon professional", I still use my old trusted friends as back ups, or I might give one of my 5D MKIII's to some of your younger reception guests and see if they want to snap off a few super fun reception photos as well.
Here is a list of our equipment. With the exception of my studio equipment we bring almost the entire gear to all of our full weddings.
Our Professional Wedding and Portrait Photography Gear