http://www.virtualization.info/ continues to be a source of some of the best virtualisation articles available
http://www.virtualization.info/2007/01/hidden-risk-of-virtual-appliances.html

http://www.virtualization.info/2006/12/choosing-between-vmware-server-and-esx.html
http://www.virtualization.info/2007/11/thinsy-announces-7th-xen-based.html

http://www.virtualization.info/2007/11/red-hat-adopts-xen-31-in-its-new.html

http://www.virtualization.info/2007/11/whitepaper-understanding-full.html

( http://www.vmware.com/files/pdf/VMware_paravirtualization.pdf )