I would like to suggest a feature that I think users may find useful. A lot of times if I have a failed test I need to debug the code to see why it failed. What would be very cools is that after the tests run, the UI provide a way to re-run any test in list. That way, after a test fails, you can go to the code and set a break point, then re-run the test again and again until you figure out what's wrong. Right now the only way to go about is to edit the main file and filter on the test. Then you have to keep re-running the entire app to run it again and again.
I can't imagine this feature being difficult to implment, but maybe I'm wrong. If someone can point me right place, I can give it a shot. I have all the source code downloaded to my machine and can complile it.
The various IDE integrations with FlexUnit, such as Flash Builder and I believe FDT are already offering this feature so if you are using once of those, you have it. If you aren't, and I suspect you are using the ui test runner, then you are correct that you need to recompile. It would not be terribly difficult, as you suggested to add that feature and if you are interested, please jump over to the FlexUnit contributor list and start a discussion on it. Frankly, that entire test runner was ported exactly from FlexUnit .9 and just made to run with FlexUnit4, so the entire thing is on the 'rewrite when we have time' list, although not formall scheduled as of yet.