I am new in Flex Development, While creating a new Mobile project it asks me if I want to Connect it to Some Servers and gives me four options `ColdFusion, PHP, Java and blazeDS
I've been doing Flex -> ColdFusion for several years and while I sometimes get frustrated with coding ColdFusion, it has been great for handling the back end of Flex applications. That said, I also use BlazeDS with ColdFusion and Flex to power (push) messaging in a couple of clients.
Ultimately, I think ColdFusion (especially with the open source CFML server, Railo) is a fantastic back end (i.e, data provider) for Flex applications.