That's asking the wrong question, in my book. The right question is something along the lines of "if companies know there are many people with that much bandwidth, what new products and services would they be selling us?"
I think we'd see more "private cloud" usage; put a secure box in your house with all your data you want to access elsewhere, give photo/video links or hashes or decryption keys or whatever to your family and friends, etc.
Looking to the broadband wonderland in South Korea of Japan w/Gig service for $25 provides some insight into the sevices/uses of that sort of broadband -- based on my experience it fundamentally changes your computing practices.