Jason D. Clinton wrote:
Others have addressed KDE 4 so I'll skip that.
As for virtualization, I would recommend KVM which is the accelerated code-base of QEmu. For example, you would modprobe -i intel-kvm and then run the same syntax as the earlier posted who used qemu. It requires that your processor has VT support.
As for Xen, kernel developers seem to agree that Xen will never be merged in to mainline because its patches are far too intrusive and manipulative. That, and I've read a number of blogs about bizzare hardware issues. In the web hosting space it makes a lot more sense--the desktop space is just too video and audio driver-ladden.
Xen was merged into the mainstream kernel last July(ish).
If the distro you use comes with Xen and management tools for Xen then that is probably the best option.