SM Pro Audio have been successfully making monitor control switchers for a while, its one of their most successfull product ranges. New for NAMM 2014 are the M-Patch Active 1 and M-Patch Passive-1.
They are identical apart from the fact that one offers a completely passive audio path and the other is active. Some people prefer the passive approach due to the neutral sound, though it does make it a more expensive unit due to the additional compoments required for truly passive attenuation.
State of the art for super-wide workflow enhancement