Massimo Re Ferre’, vCloud Architect at VMware, has posted an excellent article on Custom Portals and Backend Integrations in a Service Provider Environment
VMware, and the ecosystem as a whole, is coming out with a number of tools that interact with the vCloud APIs natively. VMware vFabric AppDirector is another good example of these tools consuming these programmable interfaces. I encourage you to have a look at the brief demo video available here.
If it isn’t clear yet, this is the reason for which developing a ton of logic right above the vCloud APIs isn’t a good strategy if SPs want to offer a VMware compatible cloud service. You want the vCloud APIs to be widely available and well exposed. Not obscured by “a ton of scripts and workflows”.
Another thing to consider before building custom logic is the associated risk of customization. Yes, this is the same old build versus buy debate but in context of security risks and how they relate to compliance. Generally speaking compliance is more complicated and expensive with customized portals. I will give several examples of this in my presentation at BayThreat.