Most people map the "fx" prefix to 2009, then map mx to the following:
Then, if the mx.swc is in the project's library path, you should be able to use the mx: prefix like you did with 2006 except for places where "fx" is now used.
xmlns:mx="library://ns.adobe.com/flex/mx" is the spark mx address, which is completely different than the original 2006 mx library.
The thing is: I love AIR, hate spark, loved the 2006 pre-spark functionality. It is so much more convenient and user friendly. Given the choice between having the display seperate from the processing, or having it be convenient and easy to work with, I choose the later option.
For the most part it seems like the AIR api is like a layer on top of the spark - flex system.. I would like to be able to over lay the same AIR functionality on top of the the old system....
Possible or no?
The code in the components did not change much for mx components in Flex 4 and later. The skins changed, so if that's what you are concerned about, I think the old halo theme still exists.
If I'm not understanding your questions, please provide an explicit example of what you want.