When working with XML, I haven't found that my programming style has changed at all, its simply the methods (or functions) I use to process the file. I have seen many cases, however, where I have seen programmers make life much more difficult for themselves by using XML.
For example, in Java, there is a wonderful Properties API that allows you to store and use simple key=value pairs in Properties file. Rather than using this, however, I have seen a disturbing trend by Java programmers toward using XML configuration files. The result I've seen is programmers using XML parsers to parse their config files and then never using it again in the program. The result is a program with external dependencies that is larger and slower than it needs to be to perform something that is done rather easily by using the base API. Java is not, unfortunately, the only place that I've seen this happening. The rush to replace all file use with XML has been an unfortunate side effect of XML, and has caused many programmers to use it in cases where other formats, including POFF (plain-old flat files) would be sufficient.