I don't think that Dubstep going mainstream will ruin it.
If you are a true fan of the music and producers then you won't care. Sure the scene might get a bit more crowded, but that happens with every genre of music.
Then there will always be awesome websites that will promote the good **** that will come out of it! (like dubstep.net, squitty, obzest.co.uk, and so many more!)
so sit back and enjoy the ride, and enjoy the music for what it is
