I just got done watching this movie and I have to say it was a huge improvement over the other movies they made. I'd say it's by far the funniest and most enjoyable of them all. As the title suggests, it has an environmental message. The writing towards the end was a little laze and all the characters were jumping around a bit though but that's it's only real fault. As usual with the Futurama movies they're written so they can eventually be broken up into "new" episodes later on (usually 4).
Originally the makers were only contracted to do 4 movies but after watching this one I certainly hope they renew and do several more! This series had so many more places to go than The Simpsons.
The DVD is worth the money in my opinion.