Advantages of Adobe Flex Data Services for MXML and AS files

[nikos101]

What are the advantages of a server that runs Adobe Flex Data Services for MXML and AS files over just compiling your flex application into a swf file and deploying onto the server?

[gnomeontherun]

(Flex Forum)

Hasn't it actually become the new LiveCycle Services? I think they extend the functionality of Flex, but not sure on that.