Today news site Ars Technica have posted up info retrieved from an internal Microsoft email:
"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."
For months internet rumors have been rife with speculation of the next Xbox requiring an always active internet connection, though now some suspect a connection will be required to install new games, essentially blocking the used game market for the new console.
You can check out the full article here.
Microsoft are set to unveil the next generation Xbox on May 21st 2013.