To be honest, I think Adobe is more than a little p*ssed with Apple right now. First, Apple changes its entire processor architecture and gives Adobe (and other developers) a major headache by making them re-code everything, with very little advance warning or assistance. That is a major task for such a complicated application suite like CS3. Then Apple makes 64-bit technologies available, but developers have to re-code everything in order to take advantage of it. Then Leopard is released, and apps have to have patches and god knows what to function properly with it (CS3 still doesn't work properly with Spaces). Now Apple aren't interested in getting Flash ported to the iPhone.
So holding back 64-bit on the Mac platform is probably their way of sticking two fingers up!