Bruce Campbell is in the movie, he's under some make up, but if you recognize his voice and style of line delivery, you will pick him right away. There is also a fright scene towards the end which is lifted from Army of Darkness, so I thought that was a cool reference.
The China Girl is just about the best character in the movie as well and unbelievably adorable.
I wasn't so sure about having a final battle in the land of oz, but the way they do it and using what we know about the wizard in the 39 movie, it is quite clever.
Mila Kunis though, her performance is fairly questionable and probably the weak link in what I would call an otherwise great movie.