Among the many limitations that the clouds are facing today, the heterogeneity of IT resources and networks. The dynamic deployment and on-demand applications are also major challenges. To ensure this deployment, it is essential to rely on methods of managing applications and services in a cloud. This paper proposes to apply the concept of Virtual Appliance for cloud architectures to ensure the dynamic deployment, interoperability and reuse of services supported by these clouds. Proposed architecture aims to solve problems of users whose are blocked from sellers with very little flexibility to move their services to other providers. Using standards of DMTF could provide more flexibility and response to user's requirement under SLA constraints.