If you have a Photographer who really understands the importance of your day it will show, and it's not by the old yes sir no sir approach. You need your day to run as smooth as possible, make sure your Photographer has all his or her kit duplicated for your own sake. How quickly can they deliver your proofs and just how much attention to detail are they prepared to pay to your day. Last but not least is your Wedding Album, I have now abandoned the Tradition Album in favour of the new Digital Wedding Albums, they are more flexible and allow your Photographer to be more creative. Don't confuse the word creative for a shedload of sideways shots trhat are best placed in the dustbin. Being creative means producing shots that are pleasing not off beat.
While on the subject of shots ask you Photographer exactly how many shots he or she will throw away, it's sometimes up to two thirds of all shots taken, I have heard of any thing up to 1000 shots being rejected out of a total of 1500. That means if your guests were expecting to find an image of themselves at your Wedding it stands two chances out of three of being rejected.
Sadly service is a thing of the past, keeping a few boxes of confetti in your camera case to hand to guests because they happened to think that all confetti has been banned can make all the difference. Just make certain that when you book for your day, ask exactly what they are prepared to do for you, your partner and Guests, after all you are paying them, make sure you are going to get the service you are looking for.
Good Luck A.