If they do make a remake, why can't they just remake Crystal? It was the better of the three games, and it would save the game creators maybe a year to 2 making 2 or even three. I would love to see you being able to choose whatever region you wanted to go after beating the E4. I think that would open up a lot of possibilites. (But, it would slow down development...)
But with all the advances with Diamond and Pearl; (the GTS, Pal Park, and the "Bonus Area"). I wouldn't be suprised with a remake...
But I wish there could be a way to tap into the old Johto games and somehow take Pokemon from them. (But since there's no way to transfer from G/S/C to R/S/E, I don't think that's possible. And let's not forget the fact, Game Boy games can't be played on a DS Lite...)