I actually like the original, and this film has its ups and downs. Here's just a few:
Ups: Most of the original voice cast returned.
Downs: I didn't like the voice of Timon's Ma. I know she did a voice in The Simpsons, but that show is just plain stupid.
Ups: We get to see Simba as a "teenager."
Downs: They wasted it with a slug-slurping contest between Timon and Simba.
Ups: It was Rafiki who told Timon about "Hakuna Matata."
Downs: How did Pumbaa find out about it?
Ups: Songs again. (some of the original songs were there, but they were just background music.)
Downs: But stupid songs. (a.k.a. Timon's solo.)
Overall, this is a pretty good movie. I'd recommend it for fans of the original. But if you don't like the original, chances are you won't like this one.
My Score: 7/10