Friends of mine got married in Middletown, Delaware last year. They had a really laid back, fun Bohemian style backyard wedding. They decided to hire a co-worker's husband to shoot the wedding. The end result was super disappointing for the bride and groom. I don't normally bring my camera with me when I am a guest at weddings. I feel as though if they have a hired professional, that's what they're there for. And I like to be in the moment when I'm a guest.
I wasn't sure if they had hired a professional photographer to capture their day, so my gut told me "just bring your camera". I'm so glad I did (and so were they)! The day after the wedding, I received an e-mail from my friend (the bride) saying how upset she was with the photos they received. First off, a red flag went up when she told me that the images were back to her by the next day. That told me that there was most likely no editing or culling done. She received all of the photos he took and NONE were edited. Overall, they were very unhappy with the photos he took.
Granted, I wasn't hired for that day, so I did not bring much gear. I enjoyed the day and took photos at opportune moments, but did not kill myself to get "the shot". These photos were pretty casual and mostly candid. Which sometimes end up being my favorites anyway. She was lucky to have "back-up" that day. It's important to do your research when hiring a photographer. Check out portfolios. Chances are, if you love the photos in their portfolio, you'll love your wedding photos!