Kakko is a pretty strong bet to become a solid top 2 line center. If you can get that with a high pick its usually very good value.
I know this is an opinion I am a bit alone of having, but I am not totally sold on his upside. To be clear -- I think you can pick him 2nd overall and come away with solid value, I think its likely that you would do that. So that is a pretty strong statement in support of him. But, he also plays a style that can be fairly containable in today's game. vPod has an offensive creativity that Kakko don't have and Turcotte got a gear in his skating and a lot of intensity that Kakko also don't have.
Is Kakko the next Olli Jokinen or will he have another gear? Jokinen wasn't a bad pick at 3rd overall, behind Joe T and Marleau. But not a franchise defining player...