The difference between the Firefox standards issue and Flash is that Firefox adoption happened across all platforms, and was not driven by a single niche market.
I'd imagine that if Firefox had never been offered for Windows, or if Windows users had not flocked to Firefox in droves, the "Requires IE" problem would still be much more a factor today.
Scoble also says
But just a few years later and have you seen a site that doesn’t work on Firefox? I haven’t.
I have. The MLS site that every real estate agent uses. It's IE/Windows dependent, as it uses a nasty ActiveX control. If you're a real estate agent in the US, don't get rid of that Windows partition or VM just yet.
What drove the "Requires IE" issue was sheer numbers. When the German and French governments are recommending their citizens not use IE, it's a pretty good motivator.
The problem with Flash is that it's not just a few HTML tweaks to fix the issue. And, for most people, Flash "just works" on almost every browser on almost every platform.
I think it's going to take more than just Apple to fix this. Smartphone makers may be able to help. But the real impetus will be Microsoft. They have the majority of users. And their answer is almost certain to be, "Yeah, don't use Flash. Use Silverlight."
