If Philly drafts Embiid, and the Celtics draft Vonleh, I think that Danny should call to see if a trade of Vonleh for Noel would be possible. Vonleh has a (raw and still developing) outside game, and a lot of potential on the defensive end. They may complement each other than a Embiid/Noel tandem who both play pretty close to the basket, and are both technically Centers. I see a Detroit situation with the two of them where the post gets too crowded.
As far as a trade goes I think that Vonleh for Noel would be decent deal for both sides. Both have tremendous potential, and it is essentially a 6th pick for a 6th pick so the money is the same.
Every year top picks are billed as "once in a generation" Elite players. But how many actually reach that point? Noel will likely never be a huge offensive threat. I don't see him ever averaging more than 18 ppg, but I see him being a 13+ rpg player with elite defense. With Vonleh, I can see him being a 20/11 guy with elite defense.
But this would hinge on the Sixers getting Embiid and the Celtics getting Vonleh.