With iOS 6, in a big way. The question of whether it's late to the party compared to the integration with other smartphone OSes isn't up for debate; it is late. But now that these social sharing features are coming, people who frequently use these services will certainly appreciate it.

Note: Facebook integration will also be a part of OS X Mountain Lion, which is now due out in July.

Speaking of social: I expect Shared Photo Streams to be a hit with families; I know it will be with mine. Here's why: Most of my family lives in the Northeast, while I live far away in Florida. Shared Photo Streams allows you to create groups that are automatically notified when pictures are added, and these photos are automatically delivered to their iPhones or iPads. For instance, I can create a Family group, and the addition of any photos to that Photo Stream group will instantly alert and send those photos to any of the people listed. Being able to immediately share selected photos with my sister, parents and assorted cousins with the tap of a Share button will be fantastic, especially since Shared Photos will be using iCloud, which, unlike MMS messaging, is a free service.

When you first create a Photo Stream to be shared, there are options to create a publicly viewable page of those pictures for family and friends who don't have iOS devices. After you select recipients, a push notification is sent to their phones. They can then view the pictures using the Photos app or, for non-iOS users, on a specially created Web page. It's a super quick and easy way to share photos with family members and friends, and, keeping with the more social theme, comments can be added.