This look awesome and I can't wait to try it out. Hell, I think we'd even use it in our office (a large open room with 8+ people working, meaning we are all often wearing headphones to stay focused).

Feature suggestion: Have an "away" feature. I hit a button to say I'm going away, type a message (brb, out for lunch, etc), and that's what is displayed in my window while I'm gone. Adding a time stamp + optional field for when you'll be back would be nifty as well. This feature could just be an extension of "privacy mode" as well.