Stu links to a piece by Simon St. Laurant on Macromedia Flash MX as well offering some interesting thoughts on the subject from the perspective of a professional Flash Actionscript programmer and XHTML / CSS designer.
I agree whole-heartedly with Simon St. Laurant's opinions on this. What kind of a web would it be where Macromedia rules the roost? Where one company says 'To make good websites, you need to buy our software?'. In my opinion, 'rich media' is like rich food, you can only handle so much of it before you have to push it away.