A good friend of mine wore a white strapless jcrew summer dress to my wedding reception in October. I didn't notice it until I got my pics back and was going thru them. It didn't bother me, prolly cuz it was after the fact and she's a sweet friend. I would never wear white or even cream to anyone's wedding. When I go to weddings I pick my dress/attire based on the venue. And of course I always try to look my best but not in a matter where I would distract the bride.
I don't understand how this thread is still going. Many social mores are followed out of respect for others. If you can't be respectful to someone or a situation for a few hours out of your life perhaps you shouldn't attend. In most places it's not actually illegal to pass a funeral procession, but most people have the decency to let them go on their way.
I'm not super-strict with fashion rules either, but this is just one of those things that I don't need to prove I'm a rebel about. Let it be about someone else for a few hours. It's the classy thing to do.
Maybe we should all stop replying here then ;-) Point is made, conclusion is: wearing white to a wedding 98% says no, 2% says yes.