A recent issue of Infoworld magazine had a cover article on Viper, IBM's new release of DB2 (version 9.1). The major enhancement is that it stores XML data in native format, not as a CLOB or BLOB. Here's a link to the article:

http://www.infoworld.com/article/06/08/14/33FEdb2viper_1.html?s=feature

Quoting one paragraph:
For starters, it gives you the ability to access
XML data using SQL queries, just like ordinary relational tables. You
can also use XQuery to access relational tables, in addition to XML.
You can even use relational SQL to limit the range of data pulled back
from XQuery expressions. DB2 allows almost continuous intermixing of
the two languages.

Our world may be in for a big change.