Tire wear

I bought an 09 Silverado in April and had the tires rotated at the end of July. After rotating them, there was a loud vibration sound coming from the front. I took it in yesterday to get it looked at and it was just that the tires were worn differently. It is going to be $978 to replace the tires and balance and all of that junk with the Bridgeston Dueler A/T. My question is will they eventually wear themselves back to where there isn't any vibration? I have driven on them since the July rotation and it almost sounds like it has gotten worse. Any suggestions for new tires that are better for highway driving? Any suggestions on what I should do? Thanks!