The gamers territory is already here for LCD's. There are several 16 ms. LCD's getting great reviews for gaming already out there. By 12 ms., do you mean 12 ms. total? Because the 16 ms. gaming LCD's that are out now are measured as 12 ms. rise, and 4 ms. fall, for a total of 16 ms. And by all accounts, at 16 ms., there is absolutely NO ghosting, smearing or trailing.
But the problem is, there isn't a single manufacturer making a 16 ms. LCD bigger than 17". And I, for one, am not willing to go that small to get the faster response time.