A new python based migration utility for migrating your xend virtual machines to XCP is now available at:
http://www.xen.org/products/cloud_projects.html
It can generate XVAs from your xend based HVM and paravirtualised virtual machines.
It can also steam your VM directly to a XenServer/XCP host over HTTP or HTTPS.
Please read the README for pointers and guidelines on how to prepare your VMs for migration to XCP. Most PV based virtual machines will need some preparation work.