Oh there are numerous differences in the new one, compaired to the old. The new one follows the book more closely, while also adding a subplot about Wonka and his Father. But the old one had a strange, strange subplot about that Wormwoth guy.
The plot about Charlie not giving the ever-lasting gobstopper to the bad-guy was a distraction, for me, in the first story and annoyed me mightily, being a huge fan of the two Wonka books.