U.S. Department of Homeland Security Sec. Janet Napolitano made it official last week that prosecutorial discretion applies to undocumented immigrants who are same sex partners with American citizens. What that means is DHS will not seek to deport such immigrants so long as they do not have a criminal record.
Such a prosecutorial discretion policy already applies to undocumented immigrants in heterosexual partnerships with U.S. citizens. While such immigrants are supposed to not be deported, they also do not gain any legal or citizenship status.