If your itunes music is DRM free you are gtg. If not you can upgrade then transfer your music easily. Not videos in itunes library. No idea about Digital copy but I would like to know as well.
From a BB user I was able to convert some movies with a BB dvdconverter, stored it to SD and now it has Transferred to the Droid fine.
Google a dvd converter and drag the converted file to SD. Most are pay but some are free.
Edit: Cleaned it up for the mods. I think.