When I was big into roller-coasters, I would regular this coaster enthusiast site for Cedar Point amusement park in Ohio. After many years of being a major fan of Cedar Point, I became friends with a handful of high up employees including people in Ride Operations, Public Relations and in Marketing. They all said they read those forums regularly. One of my friends even knew my alias before I even told him! Some of the reasons were personal (like laughing at what people thought was next), but they were also instructed by the president to keep an eye on them for various business reasons (complaints, opinions, problems, etc).
Based on this, I would agree that there are many Apple employees looking at these forums. I would bet some of those employees are even high up in the Apple hierarchy.