With the API i am developing it it will allow for searching so if TPS create there own download service they can piggy back off of my API as well to make sure everything talks to one another. Currently this is my own personal project, so registration will be needed (i am working on implementing oAuth as well, so you can login from facebook, twitter, amazon, or google). i am going to make everything as painless as possible for users to share and collaborate.
@cap, i will also make sure to have the ability to add links to other websites as well so everything can be indexed in one place. do you think that will help with the issue? to be honest it's only natural for multiple sites to pop up with this sort of service, and with existing download sites for RCT3 they may include services for TPS.