Google let you migrate machines between data-centres while they still run
While it’s a nice feature, and something that VMWare has been able to do for a while – But I can’t help feeling it’s an anti-pattern in cloud-infrastructures. Yes there are some applications that you can’t easily design as message consuming stateless data-beasts – in general to take advantage of scaling (for capacity or to money), you need to design your applications so that they can survive machine failure, be it from chaos monkey or otherwise.