The Department of Homeland Security has posted a memo from DHS Secretary Janet Napolitano outlining more specifics on the proposal leaked/announced this morning. You can read the memo here: Deferred Action Process for DREAMer Undocumented Youth
The language being used is Deferred Action, which can be deployed both in the context of relief from deportation and in the context of an affirmative benefit (for instance, this is what VAWA Self-Petitioners file for initially when they have suffered from domestic violence).
DHS states that the benefit is available immediately to qualifying individuals and an affirmative application process will be developed in the next 60 days. DHS notes that this is not a guaranteed benefit and all cases will be reviewed individually with an eye to proving that all requirements have been met.