To overcome vendor lock-in obstacles in public cloud computing the capability to define transferable cloud-based services is crucial but not yet solved satisfactory. This is especially true for small and medium sized enterprises being typically not able to operate a vast staff of cloud service and IT experts. Current state of the art cloud service design does not deal systematically how to define, deploy and operate cross-plattform capable cloud services. This is mainly due to inherent complexity of the field and differences in details between a plenty of existing public and private cloud infrastructures. One way to handle this complexity is to restrict cloud service design to a common subset of commodity features provided by existing public and private cloud infrastructures. Nevertheless these restrictions raise new service design questions and have to be answered in ongoing research in a pragmatic manner regarding the limited IT-operation capabilities of small and medium sized enterprises. By simplifying and harmonizing the use of cloud infrastructures using lightweight virtualization approaches the transfer of cloud deployments between a variety of cloud service providers will become possible. This article will discuss several aspects like high availability, secure communication, elastic service design, transferability of services and formal descriptions of service deployments which have to be addressed and are investigated by our ongoing research.