First, to put things into perspective, I take photos at weddings, as a friend of the bride / groom. I don't use a flash and I don't get in the way of the photographer.
But here is the catch, I don't get in the way of the photographer because I think that the shots where this may happen are boring as hell, you know, posed shots (in the presence of everybody).
I go for candid moments, those shots that most people either don't see, or chances are you can't overlap with others taking photos.
If the photographer plans a specific pose, that is, has a specific idea rather than going for the usual "take a shot of everybody", I can't see how anyone would get in the way, or why the bride and groom would look to someone else. If this happens, it only means that the photographer is not showing who is the puppet master and appears to the other people as "just someone with a camera, like everybody else".
I have seen hired photographers tell the relative / friend type with compacts not to shoot at the same time because of their flash. Outside this, I think that the (hired) photographer has to adapt to the situation.
I mean, okay, you are annoyed by the gal / guy with a camera, but what do you do with all those people who moved around, back and forth, crossing your lens just as you trigger? Would you throw them out of the wedding? Would tell them to stay put in their chair? Are you telling yourself "oh, crap, I can't take candids because of all these people, I can only take posed but even then there are all these people..."?