starting Jan 1 2011, when coverage comes up for renewal that is when people will be able to take advantage of some of the early provision.

also FTA:

Some coverage gains may take a while to add up. For example, Blue Cross Blue Shield Kansas City reports brisk sales to small businesses by advertising Obama's new tax credit for those who offer coverage. CEO Tom Bowser said more than 60 of the 227 small firms signed up so far did not previously offer health benefits.