Unfortunately 4th Edition is closed content and we do not have permission to create and distribute data for this game. PCGen can support 4th Edition as easily as it supports 3.5 and 3.0 and many of our users have in fact created their own datasets for 4th Edition.
Because of the interest in using PCGen for 4th Edition we have done what we can by creating a Starter Set as an aid to those wishing to code up their own data. The Starter Set is available as a separate download in the form of a data installer zip. It is kept separate because it is incomplete, it's basically an almost empty structure which you can use to start coding your own set.
The Starter Set includes a dataset which has some sample data but no actual content from the game itself. The sample data is meant to show how the data can be coded and you may want to delete or comment it out as you create your own. The Starter Set also includes gameMode files specifically set up for 4e, output sheets and preview sheets and additional documentation with instructions for creating datasets for 4e. The output sheets and preview sheets are only slightly modified versions of 3.5 sheets and still need a lot of work to be fully 4e, again this is meant to be a starting point.
The starter set itself is incomplete and its future usefulness depends largely on the feedback and contributions of you, our community. If you have suggestions, improvements to the instructions or gameMode files, better outputsheets, etc.. please post them to our yahoo group and we will happily update the starter set package.
You can download the 4e Starter Set installer from our download page or from this direct link . See this page for instructions on using the installer.
Good luck and happy coding!