I've been wondering for a while and can't find an answer to this:
SD to USB adapters exist, but is it possible to hook up an SD-to-USB cable and have a driver present a virtual sd disk to the camera but write the video directly to your computer RAM via USB?
edit: if the elgato can do it with HDMI, the question remains can it be done directly with SD out?
e2: also, SD card readers/adapters are cheap and plentiful, this seems like it should be easier to implement