This is how @dustinb3403 suggested replicating VMs between hosts:
While this is accurate, it also misses on the fact that he would still have his NLS server sitting, collecting backups on whatever schedule.
Other than that it is accurate. In Scott's proposal you are making the shift from migrating the entire workload (which is essentially instant) to migrating the database only.
In his case, the load balancer is the weak link in the chain. Granted these don't fail often but it isn't something you have control over either unless you provide your own for the COLO.
2 haproxy VMs (one per host) and keepalived for failover