Adobe Catalyst is promising in that it aims to allow designers working on Illustrator/Photoshop templates to convert them into Adobe Flex UI screens (mxml). It is "promising" because from what I've seen so far the MXML output isn't very developer friendly.

The aim, of course, is for the designer to generate the exact look and feel for the wireframes and render them (using Catalyst) to MXML for the Adobe Flash/Flex developer to code in the behavior/functionality. Catalyst will require Flex Builder 4 (which will not be out until 2nd half of 2009).

http://labs.adobe.com/technologies/flashcatalyst/

FXG (the interchange format spec - from Adobe CS to Flex):

http://opensource.adobe.com/wiki/display/flexsdk/FXG+1.0+Spe...