Most techniques to minimize render time involve a tradeoff between speed and image quality. Lower the resolution; if you're using raytracing, lower the number of raytrace bounces; lower the pixel samples (antialiasing); avoid dynamic hair and atmosphere; etc. Some of the Material Room's shader nodes (the Reflect node, for instance) have quality settings, also, which can dramatically affect render time.

Much of the pre-render wait (each frame, unfortunately) is due to shadow-map calculations. If you have plenty of memory, try using raytraced shadows instead of shadow maps. You'll need to set each light source to raytracing.