Yes, if you move it to the BE media server, you can use both devices. Just have them in the same device pool and assign the device pool as the device in each job, rather than a specific device. BE will use both devices at once if two jobs run at the same time, or will use the deivce which has the highest priority (ironically the lowest number is the highest priority)
Device priority is found on the device properties screen, but only if it is in a drive pool.
As for you initial question, technically with 10.0 if you have the Central Admin option installed you could have one machine control various remote BE media servers which each have their own hardware.