While Apple boosted that its new iOS 5 offers more than 200 new features, it showcased only 10 major features such as revamped notification system, iMessage, PC Free etc. at the WWDC 2011 keynote address due to the limited time available. Some of the hidden features are slowly being brought under the spotlight.
9 to 5 Mac has recently revealed that iOS 5 supports full 1080p video.
A quick reminder, iOS 4.3.x currently supports 720p video.