AH yes CS4. I download a trial version of it to test it out. If you don't know AS3 stick to flash 8 but If you DO know AS3 it's worth it. The only thing that is a real let down about CS4 is the new Motion tween is dificult becuas you can't copy a keyframe and paste it WHICH IS VERY ANNOYING but that why they left the clasic tween I guess If they improve that if will be mcuh better. My advice to you is learn AS3 if you want to take advange of CS4. this is the way it is. Flash 8 is for Animatiors. Flash CS4 is for devlopers.
FidioProductions
You do realise that you can get it for free? Right?