Cool news! Hopefully it will trickle it's way down to everyone else by early next year.
After this is rolled out it will be interesting what the next move for Comcast will be... If anyone wants to get on a 200mbps tier they are going to need a 8 x 4 modem. From what I'm reading you should have somewhere around 300mbps down / 100mbps up if you have 4 64qam carriers on the upstream. Given how tight they are on upload bandwidth I could see keeping it reserved and going to 25 on the upload.
So 200 / 25 sound good for the next tier they announce? :P