If you were thinking about getting a DXA for Christmas, you may want to call Santa first. It seems like the DXA-5D is back order and will be replaced (soon?) by a new product. I contacted BeachTek and the rep told me they have an alternative product coming soon.
Just a small recap, in case you did not watch the article on audio, the main advantage of the DXA-5D was that it was an interface between your mic and the 5D. So the sound was still recorded on the 5D (so no sync issues in post) but with the auto gain control disabled and with the added benefit of being able to monitor your audio while recording.
It is a bit sad because it was part of my top 5 HDSLR shooter wish list for Christmas. Have to find something else now!