So Citrix has finally seen the light and is no longer supporting OEM'd versions of XenServer. If you have Dell servers however, you might want to monitor them using OpenManage. While Dell supports a host of Linux distributions, XenServer per se (which is a stripped-down CentOS) isn't directly supported. There were a few hackish guides floating around the interpipes, but I didn't want to risk them on a production system.
Now this guy has found out how to install OMSA on XenServer 5.6 and lo and behold, there is no black magic involved. I can't wait to verify his claims. Now I'm off backing up my XenServers though ;)