I finally got my hands on an iPad2 (yes, the new job has perks) and today I decided to test out building a Flex Mobile application to the device. Others have described the steps in detail so I won't repeat that here, but I'll share how it went for me.
First off - I signed up for the iOS Developer Program this morning. Oddly I had to use a whole new login since my last login was tied to my Broadchoice job from a few years back. I saw nothing in the UI about changing your organization. I used it as an opportunity to dump my Google Apps email login and just switch to a new account. I did this around 10 or so this morning and it was done by 2. I had heard 24-48 hours so I was pretty surprised.
Next - I read Holly's blog post here: Flex/AIR for iOS Development Process Explained!. She does a darn good job. I still had a bit of confusion in some place but to be honest I skipped all the tutorials on Apple's site and I tend to skim as well. The biggest I issue I had was in creating a p12 file. Flash Builder will actually link you to a page that talks about it but I found that page to not be helpful at all. Instead this article - Using Flash Builder 4.5 to package applications for Apple iOS devices - helped me get over that hump.
Then I simply exported a release build. This process takes a few minutes on Windows, but once done you have an IPA file. Drag that into iTunes and voila - it works.
Here is my app on the iPad2 desktop (I didn't specify a custom icon)
And here is the app actually running (and no - my app doesn't actually do anything)
Sorry for the awful pictures, but I mainly wanted to prove that it does indeed work. All in all the process took me about an hour. Next time will be significantly shorter now that I know what I'm doing.