Systematic and robust condition monitoring of crucial equipment is the cornerstone of any successful preventive maintenance policy in the industrial environment. Recent advances in low-cost wireless sensor network (WSN) technologies and products indicate a promising future for a cost-effective, wider and more permanent deployment of a distributed sensing and processing infrastructure. This paper aims to provide a comprehensive assessment of main WSN technology alternatives available today, based on a qualitative and quantitative analysis of the typical range of requirements in the specific application domain of industrial machine condition monitoring.