http://www.ign.com/articles/2013/10/24/xbox-one-supports-up-to-eight-people-in-party-chat

Microsoft has confirmed Xbox One Party Chat will support up to eight players at launch.

Game Informer reached out to the company following the news of how many people the PS4 party chat would support to see if it'd be matching Sony's eight.

"At launch, up to eight people will be able to join a Party Chat at a time on Xbox One," a Microsoft spokesperson told the site. FYI, this is the same number of people the Xbox 360 will support chatting at any one time.