I just recently demoed a complete unified communications platform based on Flash and Flex2 and all I can say is wow. Pronto! Is a complete communications media center with unified communications built-in. The application has a great user interface that is faster than AJAX technology which is typically powering the latest web 2.0 applications like Google maps.
Another benefit of Flash is the system is more secure. AJAX applications are currently not quite as secure as they can be. Sure they are getting better all the time but the benefits of Flash are so great I don’t see a reason to use AJAX for such an application.
I imagine this solution took a great deal of effort to program and it is worth it as a single program can handle mailboxes with voice and video and the application can also handle videos, music, IM and more.
It is worth checking out Pronto! for your self. Visit the Communigate Rich Media Internet Communications Community on TMCnet for more information.