Microsoft/Bungie’s announcement was scheduled to be revealed just after the finish of Nintendo’s and Sony’s respective conferences (as indicated by the Bungie website). Most assume it would have been a deliberate setategic move to smother media coverage of Sony and Nintendo’s shows if needed.

Clearly MS felt they had done enough (In their eyes) that such a reveal was not necessary once they had seen their competitor’s conferences. They’ll likely hold on to it until such an announcement could be of strategic use again (eg. to counter a God of War 3 gameplay reveal at another conference).

No fanboys here (we gave MGS4 a 9.9!)… What I wrote above is purely BUSINESS.