I was working on a Flex component to display ColdFusion debug data in a usable format, but then learned that Mike Nimer had beaten me to it (and created something far more elaborate than I was planning). So, if you are looking for something akin to <cfdump> in Flex (usable with any AS3 objects, including debug information returned from ColdFusion via a <mx:RemoteObject> call), grab a copy of Mike's
Flex 2 Debug component.