Methanogenic archaea play an important role in the global carbon cycle, as they catalyze the final step in anaerobic biomass decomposition to generate methane. This physiological trait has attracted much attention for the production of biogenic methane with methanogenic archaea as an alternative to fossil natural gas. Considerable progress has been made on the bioprocessing aspects for this purpose, and bioelectrochemical systems are considered to further optimize cost-effectiveness. Genetic tools for mesophilic methanogenic archaea are long available; however, more sophisticated methodology is still in its infancy. Thus, there is a requirement to develop further genetic tools. Moreover, biotechnologically relevant species are becoming genetically accessible only recently. However, the production of value-added products, such as isoprene, with methanogenic archaea has been demonstrated at low levels. In this perspective article, we discuss some of the recent developments on bioprocessing and genetic engineering strategies and provide a brief perspective on the biotechnological prospects of methanogenic archaea.