I wouldn't give up on the chances of a Spirit Crystal, or something of that nature. If you enjoy playing the ROMs that Hackers create, then I'm sure one of them may end up making a Crystal update with it. Except, yes, the comapny is about bringing in the highest money income they can get, while still keeping their fans hooked. It is likely a Crystal Remake won't sell as much as HeartGold and SoulSilver at this time. Though, with the new release of a new generation, then I'd say it is pretty probable over a Crystal revamp and Nintendo and GameFreak knows they'll get a higher raise in sales. Not to mention, even though some may not want a 5th Gen as yet, it is very predicatable they may still end up buying it. Why? Because like Nintendo and GameFreak wants to do is keep their fans attached to the franchise and surprisingly, with all our complaints we may have, it actually works.
Not to mention, I would rather keep Crystal and Yellow a priceless original as I wouldn't want anything to be messed or tampered with too much. They are good as is, and older gamers would still enjoy playing them now as Yellow and Crystal without a remake messing a few things up.