Up until now, development for JDFeedMe has been done for JDownloader stable (0.9.580). This is the version you probably have at home today, since the developers aimed for the largest potential user group possible.
In order to incorporate JDFeedMe in the next official release of JDownloader, JDFeedMe has to be added to the current JDownloader source code (JDownloader is open source as you know). The next release of JDownloader will probably still take a few months, so the latest version is currently in beta.
The issue is that the latest beta has several significant code changes, which means the plugin code has to be modified to meet these changes.
Work on this version began during the last couple of days, so stay tuned for a new version of the plugin – this time for JDownloader latest beta!