As I and the team are writing manpages for XCP's xe command and it's 361 sub commands I'm writing more XCP tools. Last night I hacked out lshostvms.sh and xcptop.sh.
The lshostvms.sh script gives a quick list of hosts and shows numerically how many VMs are currently running on each. This includes the Control Domain itself currently but I may change that in the future.
The xcptop.sh script gives a list of all hosts and for each CPU core shows the utilisation according to XCP.