While Microsoft attempted a much more restrictive approach to distributing the still-cooking Windows Phone 8 SDK, it appears the intimidating legal ramifications didn't deter lucky members of the program to leak details and screenshots of a feature.
In this case it's the rumored "Rooms" feature, which was previously reported to be an interactive group area to share content. That rings true thanks to the screenshots provided by WinUnleaked member arseny92. Rooms live within the People Hub (under a new 'Together' pivot) and invited users are essentially syncing content between their phones. LiveSide may have explained it best: "To put it simply, think of it where 'Groups' is visible to yourself only, whereas 'Rooms' is an interactive group where people have to be invited to join and other users can contribute contents to the Room".
Here is a list of all of a Room's features, and a description of their functionality, taken from these screenshots:
Invite someone to your room to set it up. Then you can privately share a calendar, photos, group chat, and notes, all right here!
Chat: Who's making dinner? Will you be home late? Group chat keeps everyone in the loop.
Calendar: Get everyone on the same page with a synced calendar the whole family can see and update.
Photos: Here's where everyone in the room can add photos and videos for all to enjoy.
Notes: Don't forget the milk! Use shared notes to keep track of everything from grocery lists to family trips.
To check out the other three screenshots from the Rooms feature, head on past the break!
Source: WinUnleaked (Registration required)