He also tacitly admitted that he's too moderate for the base. Hence "Things have changed since 2006, or when I last ran in 2002." I like Jeb but not the guy I'd (hypothetically) vote for in an open 2016 primary.
If Obama wins this time and the Democrats have control of both houses of Congress in 2016, I think the GOP might be willing to tone things down in 2016. Or they might not. It's too soon to say if the Tea Party is a temporary blip or a sea change. And if Romney wins this time, Jeb would only be 67 in 2020, so if he stays relevant as either Veep or a Secretary, a run in 2020 is not out of the question.