Future support of the flash player will not be on the mobile browser,rest the things will be carry on to work to.
No problem in the immediate future, but it is a problem down the road. So, you have to determine if you want to build experience in a technology that is doomed to a slow death. Undoubtedly, Adobe will support it for the next 1, 2, 3, maybe 4-5 years. But, at some point, it makes no business sense for Adobe to bloat their flashplayer to support enterprise application development when they have clearly stated that a) HTML5 is the future of enterprise web application development, b) Adobe will concentrate on content, digital media and marketing. Even the most short-sighted person can put 2 + 2 together to assess what is the long term fate of Flex and FlashBuilder. Will Flex be supported by Adobe in 2 years? Yes. Will Flex be supported by Adobe in 5 years? Maybe. Will Flex be supported by Adobe in 10 years? Definitely not.