A reasonably good introduction is:
http://www.wolfram.com/broadcast/video.php?sx=CDF&v=798
It seems to me there is some tune-up by WRI to make the CDF Player easier and fully functional.
One important feature that is missing is the ability to have applications with packages and style sheets. In the example I've been working with this all works if I install the application in the Wolfram Research files, but not if I install in the user data files. Research papers might often be developed with private package code. And if there is more than one CDF document it should be possible to use one user defined style sheet for all of them.
If you are working with Mathematica installed it has to be absolutely clear how you test a deployment without interaction with your Mathematica.
And I don't understand the Enterprise CDF option. I have the Enterprise edition of Mathematica (at least I paid full price when I bought it) and Premier Service but when I try to deploy from the Menu it does not give the Enterprise CDF option, contrary to what they imply.
And when I open the example within the Wolfram CDF Player I get a message : "This notebook was created in a more recent version of the Wolfram System, and may not function properly with the older front end you are using." Why is that?
So this is not smooth and not really usable for a typical researcher. Too many snags!