What exactly does "positive camber" mean? Is that where the board curves up a bit off the snow between the feet? - yep
Is positive camber good? - You're going to open up wars here...hah. Its all preference...+camber has been around for a while and is like the "tried and true" design. "Good" is subjective. Search up the forums and u can read plenty on it and different aspects camber and reverse camber bring to riding.
Also a BA plug...heh
The Angry Snowboarder Blog Archive Camber Theories Explained