Is there any Xen alternative for VMware Infrastructure?
Any aggregation and control interfaces?
You can check ganeti from google.
Next you my check:
Next to try:
DTC Xen Tycoon Hyperic - its like nagios Bixdata programs
Some of them are only console management but some have nice GUI. Maybe one from them will be useful for you. Sorry, I can post only one link :(
If you go the Citrix way, you have the XenCenter which looks very much like VMWare infrastructure. If you need entreprise level features, this is what you really should be using.