I saw the first showing yesterday. Got my FastPass way early in the morning (was towards the front of the line), then returned to the parks and waited to get into the viewing area at 6:15. Honestly, there is no need to wait to get into the viewing area. The FastPass states to report at 7:30, and the people who didn't wait to get in got spots just fine. We cared to do nothing else, so we just decided to wait it out.
The show was incredible. The videos online, no matter how HD they are, will ever do the show justice. I went in with high expectations and was still blown away. Before I start sounding too positive, there were a few dull moments. Parts where it's just clips of movies projected onto the mist screens were just unnecessary. However, where the show really shined was when all elements of the show were incorporated and working together (lazers, fountains, projections, etc.) Some parts just felt unreal to watch. For example, in the Little Mermaid part, there's an effect where it looks as if the ocean is rising. You can see it in the videos, but the effect is truly impressive in person. I saw many people crying at the end of the show. I myself, teared up.
Robb stated it correctly in his post. If you're a person who enjoys shows like this, then World of Color is right up your alley. Otherwise, you might want to spend your time elsewhere.