I am in the same kinda situation this year.. I am going to file my H1B this april(Master's quota). I hope i will get one . My opt expires on may 12th ,,i am going to start my class from june 2nd till october. Since I don't think i will be able to send my new I-20 to USCIS this april,, which means USCIS won't send me new I-94 if my H1B gets approved. My question is ,, Is it mandatory to go out of USA before october 1st to have my H1B effective,, or I  can just go anytime later on to any country outside USA and get H1B stamped... I don't know about this situation..If any of sajhaites can suggest me something it would be great @ this dire situtation..

THanks