I've been developing Flex applications since Flex 2, and have seen FlexBuilder come a long way in that short amount of time.  I've seen demos and hints at "Thermo," Adobe's next version of the FlexBuilder IDE (aka FB4).

So I was sitting here thinking about my normal workflow process, and I started wondering if there are any plug-ins (planned or existing) to FlexBuilder that would allow another improvement in development workflow.  I know "Thermo" is supposed to offer the ability for designers and developers to work together in the same integrated environment.  This is a welcome and needed approach, however, I try to use "good" programming practices and I actually enjoy planning out my projects PRIOR to coding.  

I think an improvement to the FlexBuilder IDE would be providing the ability to allow system/project architects to integrate with FlexBuilder as well.  Sparx Systems has a neat product called Enterprise Architect which allows for UML and project modeling/management. Now, I'm notintentionally trying to plug the software, however, I have used it and it's REALLY nice.  The learning curve is mellow, but the product is extensive and thorough.

I want integrated UML and project modeling WITHIN FlexBuilder.  In a perfect world, the modeling tool would also be visual AND allow me to stub out code as I make changes to the visual model.  For example, Visual Studio 2008 includes a object modeling tool that allows a user to layout their projects, and see relationships/dependencies in a visual environment.  A plug-in or addition to FlexBuilder along these same lines would be highly treasured... especially given that I hate having to switch windows.  Enterprise Architect, as you draw your classes, methods, etc actually allows the user to create those individual classes and even goes so far as to create your files and class skeletons.

Now, maybe I'm just lazy, but providing a central location to plan, design (graphically), and develop projects in a single IDE would be amazing.