Son's girlfriend is over there this weekend so I'll have her opinion later this weekend. She is a huge Disneyland fan and has a season pass go I expect she will be positive. From what I've seen though the rides are pretty mundane - same old rides with the major difference being the vehicles patterned after the movie characters.
The morning show hosts who were on-site last week said the environment is unbelievably realistic but, to me, that is a lot of money to spend for scenery.
Oh....and by coincidence, ABC is running the movie "Cars" Saturday night. Pulling out all the stops it seems.