There's a good post over at Ajaxian about how more and more Ajax applications are taking steps to obfuscate their source code. The 'view source' issue is, in my opinion, the greatest threat to steady adoption of Rich Internet Applications out there.
I love Flash and Flex, and I applaud the team at Adobe for making the Flex 'view source' robust. But unfortunately, I don't think enough Flex developers enable view source. That's one of the reasons Ajax took off - it was easy to dig into code and figure out how to do things. From day one, the mindset of the Flash community has been for a very closed model. That's probably even why some people went with Flash instead of Ajax; they could keep the source hidden. That's unfortunate, and it's bad for Flash as a technology.