I was thinking about the benefits of having your wedding photographer at your morning preparations instead of just before the ceremony and came to the conclusion that there are quite a few benefits for the wedding couple as well as for the wedding photographer.
In case you didn't decide on a pre wedding engagement shooting this might be the first time you are meeting your wedding photographer. Yes, you'll have viewed his style, you went through his website and you know roughly what to expect during the day but with his arriving the moment has come, the wedding day has officially started and he will be on your site for most of your special day to capture all those moments you don't want to forget about. Still now is no time to pose for the pictures as you need to get ready for your wedding day. You want to look fab so no time to be wasted. From a photographer's point of view it is a quite relaxing start as you can snap around and get to know the wedding couple a little. Are they nervous, are they excited? Do they like the camera? Do they pose for the camera or are they in a rush? It's a great time to get to know each other a little before leaving the place and officially entering your wedding usually with family and friends involved.
Bottom line: You get to know the wedding photographer and he gets to know you, compared to later there are not many people involved and it's a smooth start of the wedding day.
This is also an opportunity for the photographer to take some of the macro images e.g. rings, shoes, dress, flowers, hair accessories and so on. There might not be enough time later on for the photographer to take these as he might be too busy to cover all important moments of your wedding day.
Bottom line: Time for some close up pictures of wedding accessories. Don't forget though if you are planning on taking pictures of the couple arriving you need to leave ahead of them!
Then there is also the aspect of "I don't need anyone being around when getting ready". From my experience and the one of other wedding photographer's people really like their wedding preparation pictures and appreciate them more than they had thought.
Bottom line: beautiful moments captured which weren't expected
Bottom bottom line: Get yourself a wedding photographer and get beautiful morning preparation pictures included :)