[17.1] Is porting really as easy as Macromedia claim?

Amazingly, it almost is. It certainly isn't an instantaneous or 100% dependable process, but it is smoother than anyone could reasonably anticipate. Do not, however, expect to be able to do all development on one platform and just waltz the files over without a thought at the last minute.

If you intend to develop a project for both platforms, make a serious effort to test regularly on both from an early stage, and do all final collation and polishing for each version on its target machine.