NVIDIA may have said it would only make a limited number of GeForce Titan graphics cards, but it still had enough to send to a few select gaming PC makers.
The Maingear SHIFT is one of these systems, as it always gets updated with the latest graphics card from NVIDIA and Advanced Micro Devices. It has not one, but three of them in SLI.
Go here to read all the relevant information that the Santa Clara, California-based company released, or here to learn more about the reason why a particularly strong PSU might be warranted of any PC using it (a comparison between NVIDIA GPU Boost 2.0 technology and GPU Boost 1.0).
There probably will be more custom gaming desktop announcements, and the names and brands won't be any different from those of previous occasions when new video boards, or CPUs for that matter, appeared.