I do believe that using PyObjC as the implementation target for the current THE source would be counter to the apparent goals of THE. THE appears to be very much an 'old school' Carbon app that is designed to work as a first class citizen in Mac OS 9 and prior -- I thought it was supposed to run under Carbon on OS X, as well?

In any case, if THE is to come to OS X in its current form, it will likely remain a Carbon based app. The MacPython project provides an excellent set of interfaces to the Carbon APIs on the Mac and would likely be highly relevant to the project.