Skyrimnexus may be down, but I've been working on my own custom version of it.
My version is here: http://dl.dropbox.com/u/9942986/FXAA%2BSharpen.7z
Compared to the one on the nexus I've scaled back the sharpen effect so it's more subtle and doesn't cause that harsh look full of artifacts that the one on the nexus did.
I've also disabled part of the sharpen shader that I did not use, so it may run very slightly faster.
It looks a lot better in my opinion.
Feel free to thinker with the values in sharpen.h to better suit your taste.
CoefFlou controls the strength of the sharpen.
SharpenEdge controls a cutoff value where the shader will use another value for sharpening edges. Raising the value detects more edges. I've set this fairly high
Sharpen_val0 controls the value to sharpen edges with. A value of 1 effectively disables this part of the shader so I've also commented out that section of the shader.
If you wish to re-enable it change:
//*Sharpen_val0 - (c1 + c2 + c3 + c4 + c5 + c6 + c7 + c8 ) * Sharpen_val1;
return ori*Sharpen_val0 - (c1 + c2 + c3 + c4 + c5 + c6 + c7 + c8 ) * Sharpen_val1;
There are other and possibly better screen space AA shaders out that, and many other screen space effects that could be added. Oblivion Graphics Extender v3 included many interesting filter that would suit Skyrim if ported over. Unfortunately between work and actually playing Skyrim I have little time to mod it.
There are many other things you can do to improve the graphics - some parallax occlusion mapping on the rocks, cliffs and ground would make the game look absolutely stunning .. even more so than now.
I'm the developer of SweetFX