Autonomic management of clouds has received a lot of attention by both academia and industry putting a lot of efforts into investigation of various solutions, even though the focus has been mainly on the IaaS level, while the PaaS level being less often addressed. However, with ever-expanding software environments of cloud application platforms, the self-management at the PaaS level becomes a major concern. We claim that run-time monitoring and detection of critical situations is a fundamental requirement to achieve autonomic behaviour in service-based cloud platforms. Accordingly, we present our novel vision of cloud application platforms as sensor networks — computer accessible networks of distributed devices using sensors to monitor conditions at different locations. The vision is based on the similarities between the problem domain of cloud application platform monitoring and such sensor-enabled domains as traffic surveillance, environmental monitoring or home automation. We also discuss potential benefits and shortcomings associated with the presented concepts and ideas.