"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."
Intresting email if true, BR on the next xbox, and nothing about second hand games blocking, and this wording is quite intresting...
engineered to be tolerant of today's Internet
So assuming that email is true this would indicate some for of always on internet connection other than what we have with the present xbox setup is indeed required.