Could Victini have been modeled after Celebi? I have both, but look at the two of them:
First of all, that V on their belly. Both have it in the same exact spot, in a similar curve.
Also, while Victini has very large ears, Celebi has the top of a non-bloomed plant looking thing on its head. Each head piece is a prominent detail in the character. On top of that, both of them have blue eyes and three fingers.
Next is the type. Now, this may not mean much since almost all legendaries are part psychic, but notice that Victini and Celebi are both part phychic type. Also, on a related note, they have similar base stats... The once difference; Victini has a type advantage over Celebi.
Also, the Natural Ability. Notice that each of their natural abilities have the same amount of characters into each word? This one's just crazy speculation at this point.
With all of this speculation, I get the feeling that Victini was made to be Celebi's sucessor.
Now all they need is a water-psychic.