I say keep it the same. The fighters both weigt on the same on the scale on scale day. The way it is now the fighters are around similar sizes on most occasions. So it is more of a skill based contest instead of who is bigger. If you had only one belt the champion could hold the belt hostage . Like mayweather did by fighting people that were good enough to be considered title defenses but not fighting the best in the division. What if ottoke was the champ. You get what I am saying. Also gets fighters more exporsure from other parts of the world, instead of only people in a certain region.
I'm not sure about too many weights, but its pretty ****in obvious there are way to many organizations handing out belts. Like i said in another topic, and like you mentioned, one central world body would be the best way to go, I've heard Oscar De La Hoya say the same thing, I hope he is the man to save boxing.