VMWare is now valued at $19Bn following its IPO last week. An amazing investment by EMC, who bought it for $635M in 2004.
We use the product extensively for our test and business continuity environments and are increasingly looking to use it to support production environments. As a solution it almost creates a perfect storm of benefits - quicker and easier to manage environments, much better value from server and hosting spend, reduced environmental impact. If you don't use it yet then certainly worth a look.