BT will supply the necessary box and a home hub, the home hub has ASDL in or BT Infinity inputs from the connection box, wireless connection and 3 Ethernet ports out + USB.
I was converted a couple of month ago and it was a cable swap for the Ethernet and new wireless code for the laptop and old computer I use as a spare. The BT engineer took about half an hour to replace the line master socket then go to the cab and jumper the connection and come back and finish the installation. I was told to expect 34MB and actually get slightly higher.
After suffering at a measly 1 to 2 MB I am a extremely happy bunny.