GPF has also released SDL for the NintendoDS, heres the info from his site:

The SDL port is based off of SDL 1.2.3 so some work is need to upgrade it to the latest version, still needs sound support and filesystem support.

Here is all the source code for each library. thanks to WntrMute on #dsdev for the source to libpng and zlib

Awesome news, download SDL from his site here --> http://gpf.dcemu.co.uk/