I tend to agree with you on the center issue. I'd rather trade for one, or sign one in freeagency. But someone like Evan Turner could step right in and play next to Evans. They can both handle the ball. They can both pass the ball. They both can get to the basket at will, and both are great rebounders for their position. And, both play very good defense. You would have two guards that are multifuctional and that are both in the 6'5" to 6'7" range.
I'm not saying that should happen. But there are players in this draft that will be able to contribute right away.