I personally would also like to see something entirely new and exclusive to WDW go into that space, but I also understand the reasoning behind why they would clone another attraction instead. Some folks will never have the opportunity (or desire) to travel to the other Disney Parks around the world to experience Carsland or the like. In that sense, I wouldn't mind if some form of Carsland lands in Florida. Heck, the majority of MK is one big clone of the original park in Anaheim and that turned out fairly well.
But at the same time, I'm not entirely thrilled with the rumors of Toy Story Playland possibly taking over some of that space. Granted, DHS does need some more kid/family friendly rides, but not the carnival-type ones that seem to occupy this land. Now, I've never witnessed this area myself and I'm drawing my opinion solely from what I have seen on youtube and Wikipedia. I am not impressed. I would rather see a couple decent dark rides based on some of the Pixar properties and possibly even a solid E-ticket. Wishful thinking, I know, but I can dream, can't I?