The Blackmagic Design UltraStudio Mini Recorder Capture Device is a very interesting and a highly useful device that Blackmagic has put out there. It is the "capture" aspect of any Blackmagic capture and playback device (and of any capture and playback device in general). Where a capture and playback device, such as the UltraStudio 3D or the Intensity Extreme, captures video from a camera, transfers it to a computer, and additionally lets you output the video to a display other than that of your computer's, UltraStudio Mini Recorder only performs the first of these functions. The point of capturing, as opposed to just unloading the camera's memory card into a computer, is to transfer the highest quality footage possible.
Included as a free download with your purchase is Blackmagic's Media Express software, which you're free to use to accept and encode incoming footage. Mini Recorder connects to your camera by HDMI or SDI and outputs to your computer by Thunderbolt (so you need a Thunderbolt-equipped computer, such as any recent Mac).