First of all, thanks for all the great ideas, like showing common mistakes as well as what to do right.
Some other points: Yes, I am currently a Gibson employee. Never thought of including it in my sig because I come to this forum primarily as a user; participation is not part of my job description and I come here on my own time

. The only exception to that was answering questions about Gibson's intended acquisition of CW when that was first announced. As to whether the video would be done on my own or be part of what I do for Gibson, that remains to be seen. Gibson is into educating users so it would be a good fit, but there's a lot to do at Gibson. The video might end up being a "weekends" project...we'll see.
As to people being interested in the video but ultimately not buying it, that doesn't concern me. The first two videos did very well. People asked for more videos at the time, but I said I wasn't going to do videos just for the sake of doing videos. However, I think mastering in Sonar is a video well worth doing. In addition to techniques I would also cover some of the background on mastering.
As to guitar-oriented material, that's something else I've considered. But that might lend itself more to a series of videos on YouTube or something...not sure. For now, a video on mastering with Sonar seems to feel right.
Thanks again for all your input and the great suggestions!!