You should be good. I got mine this past Saturday, the 2nd. Downloaded the app on Sunday and placed the order with no problems for a bumper. I got the confirmation email and tracking number yesterday, it's on the way.
For iPhone 4 purchases made before July 23, 2010, you must apply no later than August 22, 2010; otherwise, you must apply within 30 days of your iPhone 4 purchase. To qualify for this program, you must purchase your iPhone 4 by September 30, 2010.