Flash 8? Smack yoself.
If you are developing anything from scratch, or maintaining anything relatively small, in Flash 8 or below, then please smack yourself.
I think we can all agree that code almost always ends up lasting longer than people anticipate. I still read stats that some 80% of production corporate code remains in COBOL or Fortran and other such craziness.
I also doubt there's any arguing at this point that flash 9 has reached at least 90% market penetration. This link shows 84% back in March, growing from only 55% in December '06. That's an incredible growth rate and it'd be impressive if since March it hadn't crept over 90.
Given that we know that code ends up lasting and hanging around longer than people anticipate, and flash 9 is being adopted at astonishing rates, continuing to generate code in Actionscript 2.0 at this point in time is not wise.
Flash 9 .swfs can be generated with only .as files and a command line compiler. No binary files are needed. So finally Flash can actually be incorporated into build cycles, placed in ant files, etc.
Actionscript 3.0 is also just a much much nicer language. No more hacks. Finally done right. The VM for it will be the background of Ecmascript 4.0, and has also been donated to mozilla to be synchronously developed as the VM for it's Javascript engine! (Link here).