Some will tell you that any music made for dancing is the "Devil's music". They are not only wrong, but they are committing blasphemy by denying that God can use those styles of music for His glory.
But, do be careful of what you are listening to: Philippians 4:8 "Finally, brothers, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable—if anything is excellent or praiseworthy—think about such things." ... Also, even if the song has positive lyrics, or even no lyrics, SOME artists intentionally place sexual and violent subliminal messages within their songs (this is not exclusive to dubstep songs either).
So, if you are listening to a song, and begin questioning if you should be listening to it, your conscience has already deemed it unclean and you should stop listening to that song or artist. Romans 14:14 states "I am convinced, being fully persuaded in the Lord Jesus, that nothing is unclean in itself. But if anyone regards something as unclean, then for that person it is unclean."
Otherwise, if you have a good conscience listening to it, then don't even question it!
btw, chillstep is the new trance. post-rock is another viable replacement for trance, like Weaver at the Loom.