From the Associated Press:
The policy change, announced Friday by Homeland Security Secretary Janet Napolitano, will affect as many as 800,000 immigrants who have lived in fear of deportation. It also bypasses Congress and partially achieves the goals of the so-called DREAM Act, a long-sought but never enacted plan to establish a path toward citizenship for young people who came to the United States illegally but who have attended college or served in the military.
Obama is expected to discuss later this afternoon his new policy that gives illegal immigrants immunity from deportation if they were brought to the United States before they turned 16, are under 30, have been in the United States for at least five years, have no criminal history, have a high school diploma or GED, or served in the military.
Under Obama's plan, these young adults can also can apply for a work permit that will be good for two years with no limits on how many times it can be renewed.