They actually took the idea from LockInfo, a system utility from the jailbreak community (which is still better than the stupid notification center).
Actually, a guy from the jailbreak community is now on Apple's payroll and helped develop their notification center.
I have never jail broken my phone. I never saw the need to?
I didn't jail break my iphone 4, but I did jailbreak my iphone 2g. It was missing so many features at the time that it was something you almost had to do.
I do miss some of the themes and programs from Cydia.