Según este artículo de Ars Technica, la nueva consola de Microsoft no necesitará de Internet para jugar, pero también dejan caer que podría seguir un modelo semejante a Steam:
According to an internal Microsoft e-mail sent to all full-time employees working on the next Xbox, "Durango [the codename for the next Xbox] is designed to deliver the future of entertainment while engineered to be tolerant of today's Internet." It continues, "There are a number of scenarios that our users expect to work without an Internet connection, and those should 'just work' regardless of their current connection status. Those include, but are not limited to: playing a Blu-ray disc, watching live TV, and yes playing a single player game."
How far this offline support will extend still isn't clear. It could take the form of a fully offline mode akin to that on the Xbox 360 (insert optical disc, install game, play, all without an Internet connection) or it could be more like Steam (install and activate online but enable subsequent offline play once this has been done).
http://arstechnica.com/gaming/2013/05/microsoft-next-xbox-will-work-even-when-your-internet-doesnt/