The main enjoyment of watching this movie for me was the irony that a motion picture made by Hollywood made a hero out of someone on the fringe of the open source camp. I didn't find it unbelievable that Ryan was working as a computer programmer, and I feel almost offended at the implication that computer programmers can't be shallow and image conscious just like everyone else. Believe me, we can.
The main disappointment was that many people who saw it either missed the fact that the bad guy was committing murder, and therefore wasn't just a corrupt businessman, or that they thought that everyone involved in open source believes in liberating other people's code, or that they missed that the villain had already committed copyright infringement.
Who shouldn't see this movie: Open source advocates - you'll either feel offended at being portrayed as extremists, or, if you are one, you won't want to pay money to an MPAA movie. Computer programmers - you'll probably end up spoiling the movie for the people around you as you explain that things don't work that way in real life, although at least you can point out that they use Linux on their workstations.
Who should see this movie: People who are related to computer programmers. While they don't get everything right, it's a start at explaining some concepts.