Hi all,
I’ve been doing some work in my free time trying to get SDL running on Windows RT. Over the recent Thanksgiving holiday, I was able to get a bunch of things working, including basic video support (with SDL_GetWindowSurface and SDL_UpdateWindowSurface), mouse and keyboard input, some timing stuff, threading, and a few other things. The port is definitely rough around the edges, and could use cleanup in lots of places. It’s probably really far from being anything that could be considered production quality. Among other things, many keyboard keys don’t work, sound doesn’t work (XAudio2 just sputters and crashes, at present), mouse and touch input needs a fair amount of work, and there’s a bunch of places that could use code cleanups. DOOM is somewhat playable though, FWIW 
(http://bit.ly/SFpcYo)
If anyone is interested in trying to use the port, or modify it, I’ve posted the code to a Bitbucket-hosted fork at https://bitbucket.org/DavidLudwig/sdl/wiki/Home.
I’m going to try to put some more work into this in the near future. I have some free days coming up in December, and am thinking of trying to improve keyboard and mouse input, among other things.
Cheers,
– David Ludwig