Offer cloud hosting … where to start

Hi everybody,

I run a relatively small hosting company, currently offering shared services, vps, resellers and dedicated hosting. We use Xenserver for virtualization and I wondered what I needed to do to move to Cloud / Scalable servers. Is it software or hardware that we need?

I'm very used to virtualization, but this automatic scaling environment is not something I've ever dealt with and would like to learn from.