My cousin runs a WISP. I asked him about the feasibility of using wireless to get a 100Mbps connection of 10 miles. He basically laughed at me. He also said that interference is a huge issue; after all, who doesn't have WiFi? And are you going to spend tens of thousands* of dollars to reserve a chunk of spectrum for yourself?

*I have no idea how much this would cost, probably more than I said.