Russ, you probably remember that Aki did a linuxfb version of drawterm for Tiny Horrible Xen; I'd bet the changes could be adapted to Plan 9 Port without too much trouble, really the Linux framebuffer is pretty simple.
If you install Plan 9 Ports, check out /usr/local/plan9/src/cmd/devdraw. Russ can correct me if I'm wrong, but I think that's the only place the graphical programs interface with X. You'll need to find the places where devdraw is using X, and replace them with framebuffer code.
Not only have I watched the video, I've used acme.
VGA text is everywhere. No need to switch to Linux (and patch it), switch to OSX, use hardware than runs Plan 9, or any other restrictions. No need to run X11.
Hmm? Apart from the proportional text what would you lose? Even IBM line drawing characters should be able to simulate the scrollbars and dividing lines. Given a sufficiently high-resolution text mode, multiple columns should pose no problem, either.
Granted, I see no real reason for it, as you might as well hook the existing code into e.g. Linux' framebuffer mode, instead of porting it to curses. It would run over ssh, of course, but so does acme with X forwarding, and the best general solution would probably involve merging sam's client/server mode with acme.
Why does it need more than VGA text if it entirely text-based?