Are you talking about auto signing your app after compiling from PB? If so, It wouldn't be to difficult. It would be just a matter of setting up the needed info for each app and running a few command lines in the background. Could easily make an app that does that but not much time right now. Currently working on a couple of updates and talking back and forth on getting Cafio on the Mac App Store. That hasn't been fun.
The same for me. I am interested seeing Mountain Lion run, but fear updating my machine...
The problem with Cafio was the thing about pre-defined folders? If so: Leave the StringGadget blank and empty... That worked for me.
Maybe this could be a feature req for PB:
To have option to include the variables in the file you edit (version name etc) and certificate and then automaticly run that script you made when clicking "Publish". I bet in a years time there will be something similar to forced signed executables for Windows (should have been done 15 years ago)
On Windows, you can set some variables for .exe-information. This should be added to the Mac-IDE also. For now, I have to manually edit the info.plist. If PB would automatically fill the info.plist and sign the .App-Bundle... GREAT!
I think, I'd donate another 20 bucks to the team, just for automating this one the way you said inside the PB-IDE!