Introducing 1080p and 3D didn't require new boxes. D* might find 4k sources, get 4k signals up to the satellites and thence down to users' boxes. But how does the 4k signal get from box to TV? I doubt that can be done with current boxes.
Today I watched for the first time some 4k youtube videos on the 4k TV that I just bought my wife. Since I only get about 14mbps from the internet into my home, I was expecting an overcompressed second-rate picture, but I was surprised at how good the videos looked.
D* better get a move on.
1080p and 3D did require new boxes, you probably had ones that supported it. The H20 (original MPEG4 HD receiver) doesn't support either. If you'd had one of those, you'd have had to upgrade if you wanted to watch 3D, but almost nobody did so the support didn't matter.
I know some people believe that the HR44 may be capable of 4K, but I can't see how. AFAIK the HDCP 2.x spec was not complete when it was designed, which makes it useless for displaying 4K movies (they will all be protected by HDCP 2.x from day one)