Apple will never allow flash or any other application environment to run on the iPhone/iPad which allows users to download applications around the Apple App store. Allowing flash, or any JVM type container would weaken Apples grip on their prime revenue steam, even if it is in the customers' best interest.
The app store for the iPhone and the iTunes store run a little over break-even for Apple, according to Peter Oppenheimer, Apple's CFO. If consumers had access to the same functionality through some other means and still bought the devices regardless, you'd think Apple would be fine with that. Apple cares about hardware sales and customer satisfaction with the device. My guess is that Apple has made a judgement about the dissatisfaction that will undoubtedly result from the absence of Flash on the iPad and decided that it's less than the dissatisfaction that would result from performance, stability and battery life issues that users would experience if Flash
were present.
Apple's problem with Flash is long-standing and has to do with years of relatively poor Flash plug-in performance and stability on OS X compared with Windows, both before and after Apple moved to Intel CPUs. It's not that it's downright terrible or completely unusable—far from it. But as anyone with a MacBook will know, if you watch Flash content on a Mac, the computer's fans come on quickly, CPU use rockets and battery life suffers (compared with watching the exact same content, in the exact same resolution, in h.264 format using the QuickTime plugin rather than the Flash plugin). On a mobile device like the iPad, for which heat and battery life are critical, that sort of behaviour is a deal-breaker.
I haven't tried recently but a few years back, I found Flash performance on a GNU/Linux Gentoo distro pretty bad as well, while quick and slick on Windows using the same hardware. There are technical issues here potentially affecting performance Flash on OS X (Apple's API limitations, the fact that its browser is a 64-bit app and Flash code remains 32-bit and more) but today's round of articles on the web seem to suggest that Adobe suddenly cares about this issue in a way that it has never seemed to previously. (I'm speaking as an end user, not from knowing anyone at Adobe. That's just how it
felt.) This seems like good news—Flash on the Mac has worked appeared to work relatively badly for as long as I can remember, one update after the next, despite the promises, and if the performance and particularly the
stability problems suddenly go away, who knows what might happen?
I've used
ClicktoFlash since its release—it allows you to automatically load the h.264 versions of all content on YouTube, for example, and the resulting absence of fan noise (and improved battery life) when browsing is very welcome.
Then there's stability. Flash was also named, somewhat obliquely, the single biggest source of all Mac OS X application crashes at the last Apple developer conference, based on the crash reports that Mac users submit to Apple. See Gruber's article
here. My own experience is exactly in line with that (with some third-party widgets collectively coming in a close second).
Some people (including Gruber) suggest that keeping Flash off the Mac has become a control issue for Apple; that's certainly possible but my guess is that if the plug-in had shown great performance and stability for the last few years on OS X, it would have been on the iPad. Anyway, if Apple and Adobe can sort out their differences, all the better.