This is another great article

http://www.internetnews.com/dev-news/article.php/3820691/New+Technologies+Showcase+ITs+importance.htm

that goes into the role that virtualization plays in future IT.  Thomas Bittman from Gartner and others really get into not just the importance of Virtualization and Cloud in IT but also why it's important to use them properly.  Virtualization, like any other technology, needs to be properly implemented and managed to get the most out of them.  Use incorrectly, they can even potentially have a negative impact on IT.