The Legal Action Center today released a Practice Advisory for Requesting Deferred Action pursuant to Obama's order that I have affectionally called, "The Dream-Ish Act". An important point to note is that, while it is not clear how strict DHS will adhere to the Napolitano Memorandum, even if someone fits under the elements, it is DISCRETIONARY. As such, someone who fits under the elements can be denied. It is not automatic. Also, it is possible that if someone does not strictly fall under the elements, that he/she may still qualify nonetheless. One could argue, for example, that a person falls under the spirit of the Napolitano Memorandum and has significant mitigating evidence meriting a slight departure from the strict letter of the memorandum.
Furthermore, in all likelihood, there will be no appeal (at least for those affirmatively requesting deferred action i.e. those not in removal proceedings). So, it is important to put your best case forward, documented with significant evidence. In other words, it has to be done right.