? 
http://www.uscis.gov/portal/site/uscis/menuitem.5af9bb95919f35e66f614176543f6d1a/?vgnextoid=1d175ffaae4b7210VgnVCM100000082ca60aRCRD&vgnextchannel=6abe6d26d17df110VgnVCM1000004718190aRCRD
Q3. Which petitions and beneficiaries qualify for a cap-gap extension?
A3. H-1B petitions that are timely filed on behalf of an eligible F-1 student and request a change of status to H-1B on October 1, 2012 qualify for a cap-gap extension.
Timely filed means that the H-1B petition (indicating change of status rather than consular processing) was filed during the H-1B acceptance period, which begins Monday April 2, 2012, while the student's authorized F-1 duration of status (D/S) admission was still in effect (including any period of time during the academic course of study, any authorized periods of post-completion Optional Practical Training (OPT), and the 60-day departure preparation period, commonly known as the “grace period”).
Once a timely filed request to change status to H-1B on October 1, 2012 has been made, the automatic cap-gap extension will begin and will continue until the H-1B petition adjudication process has been completed. If the student’s H-1B petition is selected and approved, the student’s extension will continue through September 30, 2012 unless the petition is denied, withdrawn, or revoked. If the student’s H-1B petition is not selected, the student will have the standard 60-day grace period from the date of the rejection notice or their program end date, whichever is later, to prepare for and depart the United States.
Students are strongly encouraged to stay in close communication with their petitioning employer during the cap-gap extension period for status updates on the H-1B petition processing
Q4. How does a student covered under the cap-gap extension obtain proof of continuing status?
A4. The student should go to their Designated School Official (DSO) with evidence of a timely filed H-1B petition (indicating a request for change of status rather than for consular processing), such as a copy of the petition and a FedEx, UPS, or USPS Express/certified mail receipt. The student’s DSO will issue a preliminary cap-gap I-20 showing an extension until June 1, 2012.
If the H-1B petition is selected for adjudication, the student should return to his or her DSO with a copy of the petitioning employer’s Form I-797, Notice of Action, with a valid receipt number, indicating that the petition was filed and accepted. The student’s DSO will issue a new cap-gap I-20 indicating the continued extension of F-1 status.
Q7. What if a student’s post-completion OPT has expired and the student is in a valid grace period when an H-1B cap-subject petition is filed on their behalf? It appears that F-1 status would be extended, but would OPT also be extended?
A7. F-1 students who have entered the 60-day grace period are not employment-authorized. Consequently, if an H-1B cap-subject petition is filed on the behalf of a student who has entered the 60-day grace period, the student will receive the automatic cap-gap extension of his or her F-1 status, but will not become employment-authorized (since the student was not employment-authorized at the time H-1B petition was filed, there is no employment authorization to be extended).