Dummy said:
I'm definitely interested. I've been digging into FXAA and different AA algorithms, but couldn't find anything useful for still images.

By sobel based blurring do you mean blurring constrained by sobel edge-detect?
Basically FXAA isn't real AA and all it does is is blur edges based on the depth of the pixels in 3D space. We don't have depth so we need to use the edges.
I gave it a bit of a go this morning. Got ok results.
MATLAB source code, not optimized at all

Edit: The lines are a bit thick looking. I think I'll play around with it a bit more.