R.J.
You're not going to deliver Schwarzenegger... promise. On average they help develop the lungs 1-2 weeks ahead, but not the whole baby. But even if they did:
Google Image 32 week premie to 37 week premie.
At 33 weeks, they're about the size of your hand. At 37 weeks, they're still mostly skin and bone, and about the size of 2 hands.
The steroid shots won't turn your wee one into a muscled 10lb 2 foot long baby. They WILL give him a fighting chance at surviving / cut down your time in the NICU from several MONTHS to mere to weeks. ((I've spent the past several months in and out of Children's Seattle. A large number of my friends there are on months 3-4 with their preemies before they can go home, because immature lungs leading to a whole host of other issues)).
You NEED those lungs developed. NEED NEED NEED. Do absolutely anything you can to get them as developed as possible. First step to life is being able to convert oxygen in the air to oxygen in the blood stream.