This article assumes that XML is the way of the future, which is a false assumption.
XML has some significant problems.
1. Performance. I'm not talking about file size (and the resulting poor performance over networks), but about that fact that parsing XML is an intensive process. For one thing, you must read the entire data structure into memory because you must read to the closing tag. CSV has no such problems.
2. Interoperability. XML only works with new stuff and something that can parse XML. Sure it crosses platforms, but you'll find that CSV as a format is even more accepted.
Even one of the co-authors of the XML 1.0 standard has pointed out some problems with XML.
That is not to say that XML doesn't have its place. Its place is in small applications that don't deal with much data, and/or have complicated data structures that need to be represented with XML.
My impression is that XML is touted as the wave of the future by an increasingly small number of people these days.