AIR (the proper name for Apollo) looks quite promising
AIR looks simple to get started with - and it will run on Winders, OS X, and Linux. That is great - there really aren't great options today in doing this. You need a special class of develooper that knows a lot of stuff to do this well today.
AIR is cool because it uses technology that developers are already familiar with - this will make it approachable.
AIR could really be big if Adobe executes well on it.