Desktops have inferior 3d rendering capabilities compared to smart phones? Since when? Any desktop bought in the last 5 years will have an integrated or dedicated graphics chip that can at least match smartphone capabilities in this area. This can be demonstrated easily by using your desktop to browse Nokia's 3d map demo, which is equivalent to what Google is doing here. Whether WebGL is fast enough to do this on it's own is open to debate, but there isn't anything to indicate these 3d maps are particularly demanding for desktops.