iTunes video? There's no such thing my friend.
If you're referring to a podcast that you subscribe to from within iTunes to watch there and you want to encode it for your BB, then you're going to have to find the downloadable version from the creator of the video. Most podcasters will also provide direct links to download their videos should you not wish to watch it streaming right through iTunes. This video is almost always in .mp4 (which means it was encoded using h.264 most of the time) format which Super can read and re-encode.
If you're talking about actual movies or TV episodes you bought through iTunes, then the video will also be encoded using h.264 with a .mp4 file extension, HOWEVER there is DRM protection on the file to deter you from playing around with it (to protect those bullies at the RIAA and MPAA!). I personally have not tried playing with such files, but keep in mind that Google is your best friend and there are always ways to get things to work for you if you have the will
This is not to say that these DRM'd files won't work with Super, but I have to consider the possibility.