Its a cool idea, this whole idea of creating little "parallel universes" and is something that is already employed on different levels in parks such in such as in Alton Towers hotel, you have rooms themed to various rides and the crazy golf of AT is themed to different areas of the park. Even when you had Burger Kings and McDonald's, this created parallels with said restaurants through out the world. My problem with this however, is to do with scale...I mean how big should these parallel lands be? This is already being done on a relatively minor scale with Nemesis Inferno (and as someone has already said, with the Sea life centers.) being spun off from the original Nemesis at AT. I like the idea of an Oblivion, (same branding and colour palette) being built at Thorpe or a Stealth being built at AT but you really need 2 to 4 rides at the minimum to class something as a "land" and when you think about how much that would cost when you can make unique rides and themed areas for the same price -you can see why they would do the latter instead. In short I can see a parallel-attraction or 2 happening but not parallel-lands.