With the very latest X.Org code, DisplayLink
USB GPU hot-plugging now works properly under Linux.
Thanks to David Airlie's patches being pulled
this weekend, the GPU hot-plugging for these USB-to-VGA/DVI adapters now works well.
Aside from needing the Git of the X.Org Server (what will be xorg-server 1.13), also needed is the latest code for randrproto, libdrm, xrandr, xf86-video-intel, xf86-video-modesetting, and the PRIME branch of the Linux kernel (although the latest Linux 3.5-rc6 kernel is mostly set).
Keith Packard wrote about DisplayLink hot-plugging under Linux with X.Org on his rarely-written-to blog
For more information on the neat DisplayLink adapters, see this Phoronix article