I wouldn't be against free-form radio, but I don't see it happening. Makes too much sense.
I see some form of rock happening on 100.9. Jack might be the more successful of the two former Backyard stations, but their music is already covered on other stations. You can hear the Black Eyed Peas and Maroon 5 on Mix 98.7 and Y101, and Credence Clearwater Revival on Z106.7. Unless Z or some other station makes a sudden move, no one else will play the new Metallica or Avenge Sevenfold when it's released.