All the intranet projects we did using Flex didn’t have any support for browser back/forward button. It didn’t have unique URLs to bookmark nor abilities to expose URLs for the search engines like Yahoo, Google or internal website search for SEO initiatives. The issue is that we are very much used to the browser buttons and the UIs in applications we are building still has page based metaphor. Till we have UI with page based metaphor, we will need to address the deep linking issue. Flex 2 doesn’t address the deep linking issue and Flex 3 now has APIs for addressing deep linking issue.
SWFAddress has been used a lot by many Flash websites to solve the deep linking issue. It supports the most popular browsers. The blog also covers good topics on using SWFAddress. I found Ryan Christensen’s blog very helpful regarding this issue. By the way, SWFObject 2.0 beta 6 has been released.