I once watched part of someone else’s wedding video–on fast forward so we could see how much the minister shuffled from one foot to the other. Also, the end of their video featured the bride and groom dismissing each pew of people individually, with hugs, etc. so the video became a good record of who was at the wedding, which I thought was kind of neat.
(I also watched someone’s video who got married in Vegas and allowed it to be streamed onto the Web. More interesting, but still not all that compelling).
I’m not married, and thus don’t have a wedding video of my own, but I think it would be a low priority, mostly because I don’t imagine wanting to watch it again–at least not for 20 years or something, by which time I’m not sure I trust it to still be watchable due to rapidly changing technology.