Earlier today, a few images of the "Microsoft Durango XDK Documentation Setup" leaked on the internet. This document is for licensed game developers only, and it reveals tons of unannounced information regarding the next-gen Xbox to the public. Much more has been added to the documentation since the last time it was leaked.
What really threw us off was the following:
"All games will be installed on the hard drive. Play from optical disc will not be supported."
What do you think? We'd say this is proof that they will include, at least, a 320GB hard drive in the base console at launch.
We also noticed that upon installation of the documentation, all of the tools and plugins needed for developers to create games are installed to Visual Studio 2012. Older versions of Visual Studio seem to have been abandoned.