I would like to vote for this feature. The control panel should be available in HA. Having multiple control panels is not a very feasible option. I have over 100 packages, and I am moving to Enhance completely in the next 6 months or so. Having to replicate everything to US, EU, Asia, and Australia servers will not be feasible. Instead if the control panel is load balanced, has rsync, it will be easier for everyone!
Update: Tomorrow we also plan on adding resellers, they will add their customers, it will grow large. A single instance/server won't be able to handle such big loads. It is better that the whole system is load balanced.