I don't believe the SDK is available like it was back then. I think Adobe has rolled all of this into their Open Screen Project (http://www.openscreenproject.org). I believe the SDK is still available to all the open screen project partners. Apple of course is not an open screen partner. They haven't even tried...
I'm fairly certain they were being charged a great deal of money for the privilege too.
Here's a direct quote, talking about the Wii:
"Why didn't we update the Flash plugin to a more recent version?
The answer is simple: there is no way to do so. It is out of both Opera and Nintendo's hands.
The latest version of the Flash SDK (Software Development Kit) offered by Adobe is version 7, so that's what anyone who is not a Windows, Linux or Mac PC have to settle with. To support Flash on a phone or device, you have to license the Flash SDK from Adobe, and as long as they do not provide a more recent version, there is nothing you can do.
If Adobe had offered a more recent version, no one would have been more thrilled than us. It would have made more sites work, and that would lead to less frustration to our users."
I think it's all in the tone of voice there really.
So it certainly doesn't look like they're going out of their way to play nice with browser or OS developers, or that they're trying to open up the actual implementation: the program seems more geared towards getting Adobe's software onto devices, getting hardware acceleration from chipsets, and getting content providers and developers to deliver content in their formats.