I don't see Demise returning anytime soon. Ganondorf will always been around. He is the main antagonist of the series. I have no problem with him returning as the vilian. I just want him to be more fleshed out when that happens.
I don't think Demise will be back for a while... I would like to see Ganondorf again, it been a few games since the last time we saw him, and he is always going to be there, just as much as Zelda... And Ganondorf is the reincarnation of Desime.
I don't have a problem with Ganondorf he is the Vader of Zelda. I don't ever want to see Demise again though, and if I ever get the urge and I'm nowhere near my Wii, i can just load up my 3DS and beat the hell out of Akuma for my demise fix.
I definitely want Ganondorf to return! (of course!) I want them to tell more of his backstory though. Even though we've been given a few facts and he's been in so many Zelda games..I don't feel like I know that much about Ganondorf.
I'm going to have to go with a no on Demise's part, but a definite yes on Ganondorf's part. I also want a more flushed out connection on why Ganondorf transforms into Ganon. I would like to see the Trident of Power to return. It would be nice if a new villian arived on scene though, like Vaati and Agahnim, but better. I just don't want anymore Lady Gagas (Ghirahim) or anymore guys competing for the Atlas Strong Man Competition (Demise).