The world can now buy both the Glossy Black Original PSP and also the Ceramic White PSP those who follow this site will know there are such things as Faceplates and also Skins for PSPs to customize them.
But Sony like Nintendo know theres money to be made in updated versions of the same hardware or even just a new colour that looks great to more users.
Personally i see a Platinum Silver as the next PSP Colour but will Sony go for a Blue or a Pink to target a certain part of the gaming community or even introduce a new type of PSP that like Mobile Phones enables you to have a different colour when you feel like it (And if Sony pinch this idea its mine so send all freebies to wraggster )