Quoting from the XenSource official mailing list:
We’re pleased to announce the release of Xen 3.0.1 !
This is primarily a bug fix and cleanup release.
Although many of the fixes had already been cherry picked into 3.0-testing, we felt it was time to roll a new release and encourage people to upgrade.
You can download src and binary tarballs along with RPMs for common distros from http://xensource.com/xen/downloads/
As usual, you can download the source using mercurial from http://xenbits.xensource.com/xen-3.0-testing.hg
Since branching the code for the release, the -unstable tree has had some fairly major merges: support for AMD SVM virtualization extensions (3.0.1 only supports Intel VT), and an upgrade to the latest linux version (with xen as a subarch of i386/x86_64 rather than a seperate architecture). The tree is likely to be unstable for a little while as we absorb these changes, though we’d certainly appreciate feedback from users.