I think that what I've been trying to wrap my head around with DubStep is the whole 'is it good music' or 'is it just different' argument.
If, in your mind, being different is what makes new music good, well, then i guess you have found your new God in Skrillex. (and those attempting to rip off his sound)
If, in your mind, good new music is something that takes an existing genre and makes it sound fresh, interesting and pleasant, then you probably need to look elsewhere.
For every musical movement, there is, like a pendulum's swing, a move to one style, which invariably brings on a move to a style that is the precedings style exact opposite. (Rock and Roll was the opposite response of Big Band sounds, for instance) (Punk was the opposite response to Disco)
Those of us followers of electronic music have had a relatively long swing towards melodic arrangements, and it was/is inevitable that the answer to that would be darker, less organized, less conventionally rhythmic and less uplifting music. Drum and Bass started it, and DubStep is seeking to complete that. To me its all just a natural progression of music, that in reality is no different than what has come before. There will be those that embrace the new instantly, and there will be those that cling to the older styles.
Just how long the pendulum will swing in the direction of DubStep is anyones guess, but I suspect it will not be as long a reign as the previous, if only because music based on major keys and conventional rhythums generally has greater and longer lasting numbers of followers than music that relys on minor keys and syncopated beats.