Submission + - CentOS releases the Xen4CentOS project returning Xen support to CentOS 6. (lwn.net)
We are pleased to announce the immediate availability for the Xen4 virtualisation stack for CentOS-6/x86_64 The software is delivered as a dedicated repository under http://mirror.centos.org/centos/6/xen4/ and were developed with the help of the Xen Project, the Citrix Xen open-source team, GoDaddy.com's Cloud Engineering team and Rackspace Hosting.
This should help a large number of hosters more easily migrate their aging systems to a more recent version of CentOS, as well as take advantage of newer features. There have been some rumblings in the CentOS world, and this announcement seems show that they've been busy.