The news initially came from a tweet by mobile consultant and developer Will Strafach. He has since deleted it, not because it's inaccurate, but because he says the info was already known. Strafach has a great record digging into Apple's iPhone development, so it's worth noting.
A panoramic camera isn't anything terribly new. Third-party apps on iPhone have long offered the ability to stitch together multiple photos into a larger, seamless photo. The feature was reportedly hidden in beta versions of the the iPhone's software, but the performance was quite poor. But if a panoramic camera feature does make it to the iPhone natively, it'll be a first for the device.