I saw on an "unreliable" site that Everett is going to be tied to something in the time capsule. For me, this sounds plausible since he keeps showing up at the Horton house and has made a connection with Julie. No other reason for that to happen unless they are tied together in the future. Maybe Nick was a twin, and here is Everett. Or maybe Everett does not have any memory of his father because he was never acknowledged by his father or some Horton relative, never knew of his existence. Not that he would have been born at the time of the capsule, but there is some long lost Horton out there etc etc etc. Personally, I do not want him to be a Horton.