It mostly went across quite easily, apart from reading pixel values, which GWEN uses to get the colours used when drawing. It is difficult to read pixels in a texture as you don't know the format, so I had to keep a surface. Apart from that though it was fairly easy.
|SDL2 renderer Mac OSX 10.8|
|SDL2 renderer Windows 7|
Please read the readme at the Github project for more details. If you have any problems report them at the issue tracker.
[8/9/13] Premake works for Windows now.