2) Your IT department can competently replicate the PaaS experience on its in-house metal (common big tech company strategy)
The cloud is likely to do wonders for velocity, as when you have a new use case, you can "just" spin up a new VM and run the company Puppet on it within an hour or so, vs. wait weeks to months for a purchase order, shipping, installation at the colo facility, etc.
If your IT department is doing Mesos or Kubernetes or something with a decent self-service control panel for developers, then you get the best of both worlds, but you also have to build and maintain that.
1) Your needs are very static, or
2) Your IT department can competently replicate the PaaS experience on its in-house metal (common big tech company strategy)
The cloud is likely to do wonders for velocity, as when you have a new use case, you can "just" spin up a new VM and run the company Puppet on it within an hour or so, vs. wait weeks to months for a purchase order, shipping, installation at the colo facility, etc.
If your IT department is doing Mesos or Kubernetes or something with a decent self-service control panel for developers, then you get the best of both worlds, but you also have to build and maintain that.