Existing users, 
My installation steps:
Uninstall Flash Player 9. Install Flash Player 10 beta. Repair Permissions.
The last time around videos remained FUBAR'd, perhaps it's working is a part of this rebuild (as per the description of what's new in this rebuild), perhaps it was the Permissions Repair–I'd likely thank the rebuild but either way it seems to be working now and I'll stick with Flash Player 10 beta for now.
...side note; diablo3.com doesn't seem to recognize Flash Player (ANY version) via Firefox (even utilizing User Agent Switcher) but worked fine via Safari. :P
OS X.4.11 MDD G4 1GHz 1GB RAM Radeon9800 Pro
Version:
THIS beta is working for me...
Feedback Type: Commentary
Contributed by: friedchikkin Friday, July 11 2008 @ 12:21 AM PDT
Product Platform: MacOSX
Used Product For: Less than a month
Recommend Product: YES
Comments
THIS beta is working for me... - sherivan
I, too, have found that it works best to uninstall the previous version of Flash Player (as Adobe recommends), and then to install the new version. That said, I have encountered videos that are green and blocky recently, but not sure if they're Flash videos. Sometimes things just don't work.Saturday, July 19 2008 @ 10:16 AM PDT
diablo3.com - friedchikkin
I found the problem being that I was using Firefox 3.1a1 (aka "Minefield")... official documentation states that support for the Classic Java plugin was dropped so I reverted to the Firefox 3.0 Release version and diablo3.com works now.Reply to This
Monday, July 14 2008 @ 09:16 PM PDT