For nearly a year, Horizon has supported instance management. It is altogether a better tool than the Special:NovaInstance page on Wikitech -- Horizon provides more useful status information for VMs, and has much better configuration management (for example changing security groups for already-running instances.)

So... I've just now removed the sidebar 'Manage Instances' link on Wikitech, and will shortly be disabling the Special:NovaInstance page as well. This is one more (small) step down the road to standardizing on Horizon as the one-stop OpenStack management tool.