According to Wikipedia, the Dream Act
would provide conditional permanent residency to certain illegal and deportable alien students who graduate from US high schools, who are of good moral character, arrived in the U.S. legally or illegally as minors, and have been in the country continuously for at least five years prior to the bill's enactment. If they were to complete two years in the military or two years at a four year institution of higher learning, the students would obtain temporary residency for a six year period. Within the six year period, a qualified student must have "acquired a degree from an institution of higher education in the United States or [have] completed at least 2 years, in good standing, in a program for a bachelor's degree or higher degree in the United States," or have "served in the armed services for at least 2 years and, if discharged, [have] received an honorable discharge." Military enlistment contracts require an eight year commitment, with active duty commitments typically between four and six years, but as low as two years. "Any alien whose permanent resident status is terminated [according to the terms of the Act] shall return to the immigration status the alien had immediately prior to receiving conditional permanent resident status under this Act."
In a December 2010 report, the Congressional Budget Office and the Joint Committee on Taxation estimated that the November 30th, 2010 version of the dream act would "reduce deficits by about $1.4 billion over the 2011-2020 period and increase government revenues by $2.3 billion over the next 10 years." Moreover, a recent UCLA study estimates that between $1.4 trillion and $3.6 trillion in taxable income would be generated for the economy over a 40 year period based upon estimates ranging between 825,000 and 2.1 million potential DREAM Act beneficiaries successfully obtaining legal status through the legislation.