If you can find any of the Portra 400nc, I would recommend it over the 400vc for a wedding.
Weddings and saturated colours don't do it for me.
I haven't used the new Portra 400, but for weddings I expect I would prefer it to the Portra 400vc.
I used to shoot weddings using the 160nc (and its predecessors), but that was in medium format, with flash where necessary or advisable.
EDIT: By the way, this thread would really fit well in the "Weddings" forum (hint to moderators)