Skrillex for one has been very active remixing (and cashing in on) popular mainstream artist like Lady Gaga (Alejandro and Bad Romance), Black Eyed Peas (Rock That Body) and even Avicii (Levels, OK result though). Most of his remixes just get's "Skrilled up" and this brosteppy glitchy sound is easily recognizable and very popular at the moment with the younglings. The best remix he has done though, that has real musical value, has to be Cinema by Benny Benassi ft. Gary Go (no 2. on my 2011 top 5 dubstep chart).
Female pop stars like Adele (Rolling In the Deep) and Robyn (Call Your Girlfriend) has been dubstepped (Robyn by one of my favorites; Feed Me), along with Blue Foundation (Eyes On Fire) who was remixed by Zeds Dead. All fair attempts by respectable EDM/dubstep artists, but for me, they lack something.
Eos, an ambitious 15 y.o. kid (!?) from LA is going straight for the big league "dubstepping" mega hits like Maroon 5 (Moves Like Jagger), Rihanna (We Found Love), David Guetta (Titanium) and Jennifer Lopez (On the Floor), getting millions of Youtube hits. The list is endless, just check out dubstep-remix.com, a blog dedicated to dubstep remixes only, and you will find proof of that. Hell, you can even make your own dubstep remix with the.wubmachine.com.
But it's not all about just riding the "wup wup wave" or milking the lucrative dubstep cash cow, there's actually some good tracks amongst the endless list of measly dubstep remixes. While most of the crossover remixes lack artistic value, the most successful ones seems to be remixes of songs from other electronic genres. These seem to survive the transition from one electronic sub-genre to the other. Some good examples of these, that actually surpasses the original, would be:
Calvin Harris - Feel So Close (Nero Remix)
Afrojack - Take Over Control ft Eva Simons (Adam F Remix)
Benny Bennassi - Cinema (Skrillex Remix)
La Roux - In For The Kill (Skream Remix)