It Is Balloon!

Story:
Fox News:  Hunt On for Boy Believed to Have Been in Runaway Balloon That Crashed in Colorado
Yahoo!:  Balloon lands after 6-year-old boy seen getting in

My bet is that he was never in the balloon for these reasons.

No place for the boy to stow away in.
Too small/ not enough lift.  The boy would weigh about 40 pounds.  It would take a pretty good size craft to lift that much.

I hope the kid let it go and is now hiding under the bed.
(There is a chance he might have fallen off or out. I hope that hasn't happened)

UPDATE!  Kid Found:  Story