Cars Land is, as DCA proves, a can't miss project. If they build Cars Land it will be a huge success, even if they don't build ALL attractions from DCA, only RSR is a must for the success and a complete Radiator Springs village. Huge difference to Avatarland IMHO, because it is questionable if Avatar, despite it's huge box office success will spawn a franchise that becomes a lasting part of western pop culture.
But remember that Carsland at DCA added new capacity to DCA, both in terms of space, and in terms of new attractions. Now, after Carsland, DCA 2.0 can accomodate a lot more guests, which means more tickets sold. Sure, Carsland at DCA is successful, but it hasn't yet come even close to paying for the $600 million or so it took to build it. Though Carsland at DCA would pay for itself a lot faster at DCA than at DHS b/c DCA had such low attendance numbers and lack of rides, and a big empty parking lot to build Carsland on.
When you look at DHS, would adding Carsland increase guest capacity as much? The backlot tour, LMA, and some of the other things Carsland would be displace (in theory), wouldn't increase DHS as much as you'd think in terms of space for new guests. As is, DHS pulls in about 10 million a year, would that number increase to 17 million like at MK with Carsland? Doubtful, IMHO. So, you're looking at a much smaller growth in terms of annual visitors to DHS if you add Carsland, when compared to DCA, because at DHS you are destroying older attractions which still bring in guests to the park.
I figure that with Carsland, DHS would get close to closing due to capacity issues, as well as possible infrastructure issues. If Carsland is built, I think it will go on undeveloped land, i.e. fifth gate, as then you could really cycle through much more guests, and generate a faster return on investment, versus putting it in a smaller park like DHS.
From a financial standpoint, it would be hard to argue redoing 1/3 of DHS without the drastic gains possible in attendance that we saw in DCA.
