That’s indeed very sad news. Script Debugger is hands down one of the best apps the Mac has to offer.
Script Debugger’s value explorers which allow you to dynamically inspect (and even change) the objects and properties offered by a scriptable application are indispensable for me. It‘s such a useful and impressive feature that I wouldn’t know what to do without it.
I wish Mark & Shane all the best. Their work as well as their contributions to the scripting related forums is truly appreciated. I‘ve learned so much from them.