As I said.... it all fits..
Arn Anderson warned Sheamus he should really do something about Nexus.
Arn Anderson and Triple H... see any connection there?
HHH is revealed as their leader, taking out Sheamus for what he did to him at Extreme Rules... Arn Anderson's advice bites Sheamus in the ass.
You then have a completely fresh HHH as heel, perhaps weeding Nexus down to just a few members... preferably Barrett, Gabriel and Otunga....essentially becoming Evolution V2 with HHH in more of the Flair role allowing these guys to shine while still receiving the rub from HHH.
Evolution was past (Flair), present (Triple H), and future (Orton,Tista), it wouldn't make since for them to be called anything resembling as they are not past present and future.
But as I said before, I hate the idea of bringing in a big name as I see the big name taking up the spotlight. Nexus are a group of young guys taking over. What since does it make to add in Cena or Triple? Triple H is no where near young and Cena has already taken over. He's the face of the company. In real life and kayfabe.