I once considered wedding videography (which is harder than still in some respects). As practice, I shot a wedding for a friend.
One cool trick was to put a microphone/recorder on the bride and groom while they were at the receiving line. With Vegas, of course, I was able to sync and splice the audio into the video so that you could clearly hear the conversations between the bride and groom and all of the guests while the video played. Turned out very nicely.
Another thing that would be cool is to set up five microphones at strategic locations in the church. One near the bride and groom. Then record the audio combine it into 5.1 surround sound (in Vegas, of course). This would take a little skill and practice. The play back in a home theater might be pretty cool with the spacial sense of surround sound. Imagine clearly hearing the bride and groom and pastor/priest, the organ, etc. This all takes a lot of effort and time and the ROI might not be enough to justify it.
If I were going to do wedding video, I would get three identical cameras and dedicated mics on each one.
I’d have a stand alone digital audio recorder as well.
Without a crew, one camera would be a wide safety locked down. The others I’d would preferably put on remote control mounts.
It can get pricey and maybe overkill but I like to get things as right as I can. I’ve heard enough bridezilla and mother of bridezilla stories.