It sounds to me like Adobe is the one responsible for building a Flash plug-in to work with an iPhone, just as they've had to build custom versions of their plug-in for MacOS, OS X, Linux, and anything else they wanted to support.
Apple isn't going to write Flash into the iPhone themselves.... Since Jobs never said "Absolutely no Flash support", but rather, hinted that it was possible -- it seems to me like they've already had talks with Adobe about this. Quite likely, Adobe said "Hey, we're not taking our developers off more important projects right now to build this thing for your phone that's not even out yet .... but after we see how many units get sold, we'll release something for it, if it's justified."