I think we all knew it wouldn't be long after the 2014 midterms were over before we started ramping up for the 2016 Presidential election, but I was a little surprised to see something so official so quickly: I give you Jim Webb, former Senator from Virginia. http://webb2016.com/
I really liked him as a Senator, and him making it official so soon makes sense when you figure who his most-likely Democratic Primary challenger will be. That said, it's early.
Edit - Since this thread is only about who had God tell them to run, I changed the title. Thanks guys.