I switched long ago. Flex was just an personal exploratory activity, not a long term commitment. Sure, I thought about buying it a promise ring, but backed out before I was in too deep. All joking aside, I was pleasantly surprised with the environment built around Flex, and thought that it was much superior to the applet. Why Adobe thought developers would pay for the right to build application effectively on it through FlexBuilder licenses is a New Coke type of decision.
GWT may be great, but Google is too fickle in it's long term support of anything. If I build a significant application around a technology, I want something with longevity. No offense but I hesitate to plug into anything Google for this reason. Just yesterday it seems that Google Wave was going to overtake the world -- and it was cool actually. I'm actually surprised they didn't continue to back it in the form of android or HTML5 technologies aimed at mobile devices and tablets.