Remember the iPhone/iPad-related squabble between Apple and Adobe on support for Flash?
(Jaded Consumer offers some opinion here and here on Apple's nonsupport of Flash on new platforms.)
The next chapter, after Microsoft's decision to support iPhone by sending it H.264 instead of expecting iPhones to speak Microsoft-ese, is here. Virgin America has dropped Adobe's Flash to court iPhone users. Virgin's experience was interesting: its site used Flash for things like transitions between advertisements, which could be adequately handled without the heavy load of Flash. Logically, Virgin dumped Flash because it didn't need the headache and it didn't want its customers to have to endure the wait, especially on thin-pipe clients like roaming mobile devices. Apple isn't moving to support proprietary plug-ins, content providers are moving to drop the crazy expectation that client platforms will install proprietary plug-ins to support the content they want users to get hassle-free. By standing with standards, Apple seems to be winning the Flash chicken game by waiting for the world to take advantage of improving standards.
Given that most folks' use of Flash seems to be to show video, HTML5 could lead lots of sites down Virgin's path toward avoiding the headaches caused by Flash.