Major Nelson just announced today that a few major changes are coming to the Xbox One and WIndows 10 versions of party chat. Previously limited to a maximum of eight players at once, the limit will now be increased to 12 chatters simultaneously. In addition, there will even be a party text message option that will function similar to your cell phone's group text.
Other features are an expansion of the TV Guide as well as the triumphant return of avatars. Finally the avatars are back and they will be animated as well. We will be able to choose between our standard gamerpic or the avatar, which will move like it does on the Xbox 360. The changes are available now to preview members of the new Xbox One experience and will be out for all later this year.