I think you can safely say any Flash iPhone app is going to be larger than the Hello World app. The only issue in question is how much larger.

Again, the Hello World App is entirely irrelevant -- the question is whether a real world Flash iPhone app will be substantially larger than a native iPhone app that does basically the same thing.

To clarify the point with an example, a one line hello world python script when compiled down to an executable on Windows takes about 7 mb of space because of the runtime payload. But, a more complex 1000 line script wouldn't take up much more space - maybe 7.2 mb