I got an email from the NYT:

Dear New York Times Reader,
Today marks a significant transition for The New York Times as we introduce digital subscriptions. It’s an important step that we hope you will see as an investment in The Times, one that will strengthen our ability to provide high-quality journalism to readers around the world and on any platform. The change will primarily affect those who are heavy consumers of the content on our Web site and on mobile applications.
This change comes in two stages. Today, we are rolling out digital subscriptions to our readers in Canada, which will enable us to fine-tune the customer experience before our global launch. On March 28, we will begin offering digital subscriptions in the U.S. and the rest of the world.
If you are a home delivery subscriber of The New York Times, you will continue to have full and free access to our news, information, opinion and the rest of our rich offerings on your computer, smartphone and tablet. International Herald Tribune subscribers will also receive free access to NYTimes.com.
If you are not a home delivery subscriber, you will have free access up to a defined reading limit. If you exceed that limit, you will be asked to become a digital subscriber.