Eric Slivka, over at MacRumors:
Apple has improved feature support for the iPhone 3GS, adding shared Photo Streams and VIP mail filtering. The change was noticed by a number of iPhone 3GS users, and Apple has confirmed the removal of those restrictions on its iOS 6 preview page.
A number of commentators noted that the omission of these features on the iPhone 3GS seemed odd. Nice to see this consistency of the feature set, rather than artificial limitations for older hardware.