Java on desktop machines. Can anybody explain the point?
What's a desktop machine? Seriously. ;-) Unless you're spending serious money, your average "desktop" is about as powerful as your average "server." The difference is in the software, yeah? There are some innovative products out there, e.g.
http://www.seamicro.com/, but most modern data centers expand horizontally using off the shelf servers built with rebranded commodity components. Google's a great example, despite their nifty containerized data center design.
EDIT: Re: Java, I run local copies of ColdFusion/JRun. That's about it.