This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
I do not consider Flex as a good platfrom for creation client application, so JavaFX is certainly better approach. Many big companies as Microsoft and Google are working on JavaFX, so it is time to start using it.