answer:• For people under 26 it will make an immediate difference. The bill lets such people maintain coverage under their parents’ plan. • For people with pre-existing conditions, the bill sets up a high-risk insurance pool, and (I believe) soon after outlaws insurance companies from denying you coverage. • Many of the bills more substantial changes don’t go into effect until 2014. Even then, for many people—i.e. people who already have insurance through their employers—it won’t make much difference at all. It may help to contain costs, but probably not by much. • For people with individual health insurance it will make it easier to buy insurance and cheaper through the exchanges. • For the rest of people, i.e. people without insurance, who can’t afford it or who are too sick to get it, the bill will make a huge difference. It will give them money to afford coverage and force insurance companies to not screw them over. More details here (NYT).