I would have thought this happened already, but perhaps that's my fond memories of my brief stint with Bid for Power some years back.
BFP is the first thing I thought of when I saw this, but this is an entirely different (and entirely avec Toryiama legit) project. You can create your character as a child from either the Saiyan, Namek or Human races, and the child will grow up as the game progresses.
Seems interesting, but I'll probably never play it. Chances of it coming to the US are slim, but not impossible. DBZ is still pretty popular in the west, but it's nowhere near popular enough to make a dent in WoW in the MMO space--or even FFXI for that matter. I won't be spending money to import it either, despite my efforts to be learning Japanese.