Jerry,
The only program to transcode the EX series mp4 files is ffmpegX, ffmpegX.com Compressor doesn't work with these files, "Error trying to open source media file."
You can open the transferred file (that is re-wrapped as a QuickTime .mov) with Compressor to transcode to DVC ProHD, but then you could just use MPEG Streamclip as it is much faster and easier and can batch transcode many clips at one time. www.squared5.com
And again you need FC 6.0.2 to edit with the XD Cam EX series codec.
Working with EX series XD Cam HQ recorded files produces many files inside the BPAV folder that are needed for what various NLE's and computer platform you are working with. You will need the 2.7 XD Cam Transfer software to convert the raw XD Cam files to a QuickTime .mov to edit in Final Cut. With file based media you must use a well organization file system and learn to guard the BPAV folder only placing it inside a separate folder of it's own and naming it properly for archiving. This BPAV folder must never be place with any other BPAV folders and must always be kept in a separate folder to work properly with the XD Cam Transfer software. To work in Final Cut you are going to use the XD Cam Transfer software that makes new .mov files and you must find a place for them to be stored as well. At the end of your edit you have choices to either keep both the raw XD Cam files (mp4) and the new Quicktime .mov files, I keep them both or if I don't have the storage room I keep the raw, this allows me the ability to work on any software platform (PC or Mac) later. You can use the new Clip Browser version to transcode to other codecs and to prepare for SD DVD archiving.