I have to say I don't understand the purpose of this e-mail within Microsoft. Maybe if I worked there or could at least read the whole thing it would make more sense. As it is, it just looks like the e-mail is meant to address the rumors directly, yet it was supposedly sent to full-time employees working on the next XBox... all of whom should already have known everything spelled out in the e-mail.
This line just seems like it's phrased weird, too: "Those include, but are not limited to: playing a Blu-ray disc, watching live TV, and yes playing a single player game."
Specifically, "and yes playing a single player game," seems like a poor use of punctuation for an official, internal business memo. Shouldn't there be a couple more commas in there? "and, yes, playing a single player game." At that point, you may as well get rid of the "yes" entirely, since it sounds pretty unprofessional.
Anyway I don't really care; it will probably will not need a connection to play disc-based single-player games, regardless of the legitimacy of this e-mail.
Question though, doesn't the 360 boot all of your downloaded games as trials while you're not online?