Of the choices left in there, I would say 3-5 years, simply because while I would love to see Shawn go into the Hall of Fame in 2011, I do not see it believable, but I do believe that Shawn will go into the Hall of Fame rather quickly.
Over 5 years would be too long for Vince to induct one of his most loyal workers, and never would be a ridiculous thing to assume, so by elimination, the most obvious choice would be 3-5, which also seems a legitimate length, I would go with 3-4 years although as the best possibility.
And that is because I doubt Vince would take too long to induct a guy like Shawn, who we all know Vince can make money off inducting, Vince loves money, and while you'd assume he'd induct him instantly then, I don't believe that will be the case, because as far as I recall, Vince has never inducted a guy the same year he retired, who wasn't called Ric Flair.