A design company out of California had posted (and has since removed) a compilation of images from apparent design work they created for The Wizarding World of Harry Potter, slating to open at Universal Studios’ Islands of Adventure theme park in 2010.
While I am personally not a big enough fan of Harry Potter to elaborate on what is included in the images, one WDWMAGIC.com poster named “darthjohnny” seems to know what he’s talking about:
There [are] sketches of what appeared to be the a giant snake (the Basilisk) in the Chamber of Secrets. Also, in one other scene, it looked like you passed by a giant spider (Aragog?) and went into the Dark Forest.
If I’m accurate about this, plus taking into consideration the rumors of a Flying Car Ride, I would say the Dark Ride is definately based off of the second book/film, Harry Potter and the Chamber of Secrets (as opposed to a vignette of different Harry Potter scenes or an entirely new story).
Update: We have now been told that the image is not exactly “new.” It has been online for nearly a year. But if you haven’t seen it before, then it’s new to you!
Update #2: We were contacted by the aforementioned design company and asked to remove the concept art and all references to the company by name.