I feel lucky just to get even DSL. I am 11k wire feet from the CO box. They currently have me rated at 8Mbps, and it is a good day if speedtest.net can clear 6Mbps. 768Kbps upload.
I would love an upgrade to better performance. I don't know if the technology exists though. That is a long distance to push bandwidth through a plain old copper pair.
Now to think outside the box... There are two pair of wire running to my house (standard just in case I wanted to add a 2nd POTS line). I wonder if that 2nd pair could be used to increase the overall bandwidth??