I think this would be a fairly easy update for the dev team. If we had the data files in XML, it would be soooo much easier to analyze them with 3rd party software.
For example, I often want to look at various things in our shard's data files, like who has the highest of skill X or who has the most money (across all banks/containers). Right now the only way to do this is with some intensive perl regex. If we had the data files in XML this would be a thousand times easier to manipulate and analyze.