Why everyone is acting like theres no pixel shaders? Those can easily do the job and it would leave much more resources for GPU, if this technique is used. As for CPU, lets see the cost of this technique.
"Linked off Real-Time Rendering, Alexander Reshetov's Morphological Antialiasing Paper is quite awesome. Unoptimized approach is about 150 cycles/pixel in a CPU implementation. For real-time performance, I bet you could amortize the cost of something like this over multiple frames!
EDIT: Yeah, after a second look, amortizing this over multiple frames would be tough! See second post..."
http://farrarfocus.blogspot.com/2009/07/morphological-antialiasing.html
Its tied to amount of pixels. Lets choose resolution 1280x720(I guess this one was used in saboteur). That would mean 1 280 * 720 * 15 = 13 824 000 cycles for each 1/30 second(saboteur again?). That means 414 720 000 cycles per second. Cycles per second mean hertz, but as we know hertz really do not tell the whole story about computers ability to calculate. So we have to use MIPS, which is Millions of Instructions Per Second. Lets say one cycle is one instruction. I think someone mentioned i7. i7 can do 76 383 MIPS at 3.2 GHz, which means smoothing 1280x720 picture with morphological antialiasing will take about 415 MIPS. That means smoothing such a pic takes 415 / (76 383 / 100) = 0.543314612 percent of computing power of i7. Oh, and did you see the unoptimized word in the article? :)
(If cycles = herzt, it would mean that smoothing such a pic would take about 13% of computing power of i7.)
