i really would like Gannon to return, and i would like to see him in his beast form again, ala ALttP. Games like that and TP, and MM with a darker/creepy tone, not to mention the chance at a dark world to explain Gannons Beast Form. AHHH, Its all coming together.
Something else that dawned on me; if they were to bring back Demise, it would have to be way later, as in real time, like 3 or 4 games from now. Also i think the best way to do it would be later in the timeline again, after gannon has failed twice, and then again when his demons failed to Revive him in AoL. Like maybe (though weak) the entity still lived and was aware of Gannons failures and grew stronger as he got more angry at gannons incompetents. So he finally is strong enough to manifest a form and wreak havoc on hyrule! not bad huh?