Depends on, firstly what they do with each exchange and, secondly, how far you are from the nearest fibre breakout.
some exchanges are just going to be fibre to the exchange, these will give about the same speeds to the consumer as are already available
Some will be running fibre to street boxes and then the last leg to the consumer will be copper, these would be capable of supplying upto about 40meg to the home, but will probably be capped at about 20meg.
Other locations will go to full fibre into the home, these (lucky) people can probably expect speeds upto 100meg into the house.