Why not Flex?
camwest: We're using the upcoming Flex 4 for a new project and I'd compare Flex to GWT but not something like jQuery. It definitely has its trade-offs and benefits. The state management and skinning system is first class and there are some great micro-application architectures being created in the Flex world.We have started to see the same sort of thing in HTML/JS land (Sproutcore/Cappuccino) but honestly, they come with almost all the same tradeoffs as Flash does.I would say the File upload/download, animations, skinnable components, layout management, and more in an single well thought out package outweighs anything in the HTML/JS land currently. Sure if you want to patch together components you can get all of the same things, but that's like arguing insert flavor of linux is as fun to use as Mac OS X because it has all the same features.I choose Flex for the same reasons I choose Rails. It's not a chore to develop in.