But recently I found out that AS3's power comes with a price. What is the price? Lengthened development time. I would need 4X the amount of time to complete a game using Flash CS3's Actionscript 3 compared to previous flash version's Actionscript 2. Why? AS3 is a lot stricter and it uses lots of classes. I myself am a multimedia author and I started out making flash movies using just simple scripting. I can do programming too, but I always took quite long during my C++ days, to debug errors and stuff.
Therefore, I decided that the best way for me now is to stick to AS2 and use AS3 only when needed. AS3 would be for games that require lots of particles and have a possibility to lag, like shooting games or 3D-rendered games. The rest, I would be better of using AS2. Thank God, I could still use AS2 in Flash CS3!