I was very saddened to hear the news that Microsoft shut down the ACES studio and as a result has ceased development on Flight Simulator. This obviously impacts the development of SquawkBox significantly. Unless Microsoft resumes development, I very much doubt there will be a version beyond the recent 4.0 release.
It has been a lot of fun working on SquawkBox over the years. I have made friends all over the world, learned a ton and had a great time in the process. I hope those of you that use SquawkBox will continue to derive enjoyment from it. See you in the skies!