Per this, the USCIS (United States Citizenship and Immigration Services) is getting ready in case the Obama administration is able to pass comprehensive immigration reform, aka amnesty:

Currently, the citizenship agency can handle applications from about six million immigrants a year, (USCIS head Alejandro Mayorkas) said, including the time-consuming collection of fingerprints and other biometric identity information. Under some plans for legalization, the agency might receive that many applications in a few weeks.

An example of the planning, Mr. Mayorkas said, is an effort to improve the agency’s ability to receive applications via postal mail at secure reception points known as lockboxes. The agency currently receives about 65 percent of applications through lockboxes, which is more efficient than receiving them through local offices. The agency is trying to move quickly to receive all applications through lockboxes.

One idea calls for illegal immigrants to start the legalization process by verifying their presence in the United States through a simple registration form mailed to a lockbox, according to officials familiar with the planning.

Needless to say, the possibility of millions of applications in a few weeks would lead to massive fraud and possibly terrorists getting on the path to citizenship.

And, article author Julia Preston of the New York Times says that the preparations being made now "contrast" with those made by the Bush administration. I don't know what she's talking about, and she probably doesn't either. See 2006's "Bush Admin Hiring For Guest Workers Program as if Done Deal" for some of the preparations they were making, and see also Burdened DHS: 10s of thousands get green cards before background checks for a calculation that - if FBI background checks were done of each applicant - it would take five to ten years to process 10 million current illegal aliens. The questions Preston should be asking involve just what corners USCIS intends to cut, but obviously she's not too interested in pointing out what would go wrong.

See all the entries at the last link for more information on this topic.