I know many dubstep styles don't use the "wobble" effect at all, and that the "wobble" effect is used by many other genres, so it's not a defining characteristic, even if it's sometimes considered a genre's cliche.
Wikipedia includes some characteristics:
tightly coiled productions with overwhelming bass lines and reverberant drum patterns, clipped samples, and occasional vocals
But that applies to a huge chunk of the electronic music universe. The rhythm section further specifies:
Dubstep rhythms are usually syncopated, and often shuffled or incorporating tuplets. The tempo is nearly always in the range of 138–142 beats per minute, with a clap or snare usually inserted every third beat in a bar
But that also applies to a huge portion of electronic music. It applies to them all if you consider the pitch control of a dj context. It's not rare to see house, techno, and trance productions with those characteristics, that would be hardly considered dubstep.
If that's not it, then what is defining dubstep as a musical genre? Which are the patterns that define a dubstep song? Is it possible to define dubstep in more precise, less generalized, terms? What makes a dubstep song a dubstep song, that isn't shared by pretty much every other electronic music genre?