There was/is a plan at the corporate level of Attractions management to "re-purpose" Disney/MGM into a thrill park. Given the success of 'Tower' and 'Rock-n-Roll' the suits thought they could keep the 11-29 year old demographic that's now going to Universal Studios and Islands of Adventure.
And by "coaster", don't think of some massive MegaCoaster soon to be featured on the Discovery Channel. The largest coaster was to be a clone of California Adventure's 'Screaming' (complete with the steel/wood "themeing"). The rest of the attractions, and probably what would go into the 'Hunchback' location, would have been nothing but a wild mouse coaster along the lines of Dino-Rama's or 'Mulhulland Madness'.
This plan had a very low probablilty of ever being put into place and it's even more remote today. Whenever executives at the top change, the first thing they do is to cancel all the plans created by they guy they just shoved out the window. And more importantly Disney isn't going to spend a dime on the parks unless they're forced to. Considering the attendance problems at DCA, Epcot and Animal Kingdom, the Studios are well at the back of the line.
P.S. A very similar plan has been created for Epcot as well: mall rides in World Showcase.