That's exactly what DisplayLink has managed to achieve with the new DL-3000 series. Over a USB 2.0 connection, you can get two video feeds of up to 2048 x 1152, including support for 1080p HD video. Bump that up to USB 3.0 and you get up to 2560x1600 resolution on two screens, as well as the possibility of getting Gigabit Ethernet and up to 5.1 channel audio. and yes, they have HDCP 2.0 for protected video playback too.
Another interesting product is their "zero client" solution. This can effectively take one computer and have it offer ten separate sessions on ten different stations. Each station only needs a sub-$100 device that can then connect to a monitor, keyboard and mouse. This can be done over USB 2.0 with solutions for both Windows and Linux.
We've got lots more coverage from Computex on the way, so stay tuned!