(I am aware that skrillex is not the originator of such a bass type. But his is just the example I'm using)
If you listen at 2:20 you'll hear the bass part and the cut up vocal thing at the same time. Notice how they sort of go together? It's because they do.
The key elements to making this sound are a super awesome sharp bass synth, a vocal (or vowel) based modulation source, and resampling.
The example I created used a reese patch I made for Massive (If you caught the Harmor intro already, the nifty sounding dirty bass it demonstrated would do just fine. As well, something you could make with Sytrus). I ran it through the Vocodex using a part from the "My Body" project vox through a granulizer channel. Vocodex has some extremely awesome morphing and bandwidth options which help immensely.
Afterward I recorded the lick there into Edison where the resampling began. The edison time stretching options for the "pro" variants have extra goodies in them than just the one available in the basic sampler channel. Specifically, the formant preservation options. Messing with this, bouncing it, and doing it again, are what I did to make the "after" portion of the lick there.