Oh, I was going to say why the hell is this thread here but then I guess it promotes some competitive discussion indirectly.
Can we not talk about Pokemon that are already great? Honestly, Bronzong and Gyarados are fine. They do well in OU. They have flaws, yes, but that doesn't mean they're bad due to typing.
Perhaps talk about some of the UUs/RUs/NUs and their performance in OU if their typing were to change. For instance, the Articuno mentioned earlier on is a pretty good example. Ice itself is a pretty terrible typing (Cloyster being the only Ice-type in OU... barely). Maybe Articuno, being the flying wall it is, would just love Steel/Flying. All of the resistances on the special side is just awesome (Ghost/Psychic/Dragon [the biggie]/etc), though yes the Fire/Electric weaknesses hurt it.