Have I got your attention? Good. Because I want to assure you that I have no special insider knowledge. I'm just a guy with a keyboard.
That said, the Clairvoyant on Marvel's Agents of SHIELD is totally Dr. Samuel Sterns from The Incredible Hulk (2008) - portrayed in the film by actor Tim Blake Nelson. In the comics Sterns is better known as the super-villainous Leader.
What has led me to this conclusion? Three things:
1) It fits with the character's skills and power-set in the comics;
2) Nelson, the actor, has appeared on TV before (of particular interest: his leading role in the short-lived 2011 CBS series CHAOS);
3) Emil Blonsky, aka the Abomination - who likewise featured prominently in the aforementioned film (portrayed therein by Tim Roth) - was recently mentioned on Agents of SHIELD (in the 2/4/14 episode, "T.R.A.C.K.S.").
EDIT 4) Actor Adrian Pasdar has recently been confirmed for an upcoming episode in the role of Major Glenn Talbot. That's right - another Hulk villain.