Virtualziation is an amazingly useful technology. It lets you run multiple operating systems (same or different) on a single piece of hardware. You could for example, run a second copy of Windows 7 on a Windows 7 PC to test software before installing it on the actual PC. Or, you could run something entirely different like running Windows 7 in a virtual machine on a Mac running OS X or a computer running Linux.

Virtualization leader VMware demonstrated virtualization technology that allowed a Android app to run on a phone running Windows CE (presumably the author meant Windows Mobile phone that is based on Windows CE)...

VMware demos mobile app virtualisation

This is amazing stuff. But, don't expect to see BlackBerry apps, iPhone apps, or even Windows Mobile apps running on other hardware platforms. These are closed eco-systems. You can't buy a BlackBerry, iPhone, or Windows Mobile OS (Windows CE is a bit different) in a shrinkwrapped box and figure out a way to virtualize it. Google Android, however, is Open Source and will be, I think, the big winner if mobile virtualization ever takes off. It would give Google Android app developers the ability to achieve the old Java language dream of "write once run anywhere." The problem VMware and Android developers will face, however, is the huge number of underlying hardware feature differences: Cameras, GPSes, compasses, etc. It will probably be very hard if not impossible to create hardware dependent multimedia Android apps (like Augmented Reality) that run in virtual machines on all kinds of phones.