The worlds are definitely not interesting and not a step up. They are boring and the game has pretty much no story in the only 2 worlds I bothered to complete. I hated it.
There's a video on nintendo's site that will get you hyped for the wii U! http://www.nintendo....me-lineup-video It's also a good way to quickly see if you want any other games.
Note: Not all of these games are launch day. A lot are launch window games.