Major Nelson's blog – that the new Xbox "guide" will retain the blades-based interface, although it's still a little confusing as to exactly how.
In his update, Whitten says: "For everyone who loves the blades interface, it's not going away," and that "every feature and option [the blades offer] is available right from the guide." Confused? You're not alone. It sounds to us like a sort of "classic view" will be offered ... but, at the same time, like the guide will simply offer the same features. We took a vote and came up 50/50 on it. We'll be sure to press Microsoft for more details as E3 plays out.
[Update: Microsoft has demo'd the revised blade functionality to the media. Pressing the Xbox Guide button now brings up a more compact version of the blade-based "dashboard," rather than the traditional single pop-out Guide blade.]