Nomura has confirmed that Ven being in Sora's heart had nothing to do with him receiving the Keyblade after it did not go to Riku.
Ethy, as far as I remember you already got into a debate with Grass once on this.
Nomura did not confirm that Ven's heart being with Sora had not anything to do with Sora being able to wield before the KK choose him for real in Hollow Bastion.
The only thing Nomura confirmed was that Sora didn't inherit anything from Ven nor anyone else.
Sora's powers are all his own, but that doesn't rule out Ven's heart having any indirect influence.
Here's the bit from Nomura:
Spoiler Show
– So, it’s not that “once Sora’s story is over the story of a new hero will begin”, but that the series will always have Sora as the hero, isn’t it?
Nomura: Yeah. One of the concepts of the series is that the hero Sora isn’t some special being, but a normal boy. Sure, his heart is connected to Ventus and the others, but other than that, he’s a normal kid that could have come from anywhere, that hasn’t inherited anything from anyone. I want to make Sora a character that will give the player the feeling that “even if I’m not some special being, I have the possibility buried inside of connecting with many others to accomplish things”.
EDIT:
@Dawn Rebirth:
There is no "official" keyblade of the RoL or RoD and the KK is also no "leader". Read my earlier post on the types of keyblades again, there are as many as qualified hearts exist.