XML and RDBMS
This is an interesting piece on the co-evolution of XML and relational databases. I agree with a lot of the points and espeically with the idea they can be used together very effectively. I wasn't initially a fan of the XML type in SQL Server 2005 and it does have its warts (so, how do I update a schema on a column?) but I think it is a decent level of integration because it makes XML a first-class citizen in the database, not just a CLOB.
My favorite quote: "Memory is the new hard drive and hard drive is the new tape drive". Interesting thought.