One thing --- you have thoroughly corrupted my memory ;p. In Windows, by default, Alt+PrtScr captures the current window. In Screenshot Captor, Alt+PrtScr captures the entire work-space (at least by default). Therefore, when I'm speaking to someone, I have to double check myself, as I am now used to Alt+PrtScr capturing the whole workspace.
Of course, making such a change now might upset existing users. That said, they might be supportive of it, new users would like it better, it would jive with traditional Windows tips and tricks, and existing users would adapt with a little time.