|Marlin cautions Dory about the pretty (dangerous) jellyfish|
As far as the 3D adaptation is concerned — yes, I had to come back to that — like the recent re-release of The Lion King, the 3D doesn't seem to add all that much to the movie. It doesn't harm it, either, but if you can catch a 2D showing, it will still be worth your while.
Finding Nemo is great on a large screen. And the bonus Toy Story opening cartoon, Partysaurus Rex, featuring Wallace Shawn, is a lot of fun, too.