We've seen this set of rumors, supposedly coming from someone whose uncle works at Bungie (oh dear God not again--Ed.) several times in the past few days. They were even translated into French at Halo.fr.
Given that Bungie seems to be enduring some kind of self-imposed silence bordering on self-denial with regards to the very existence of Halo 3, even to the point of failing to confirm or deny the existence of the game after it was referred to by no less a personage than Microsoft chairman Bill Gates.
That, plus the fact that historically Bungie, like other game studios, usually doesn't comment on rumors, means that regardless of the particular situation right now, these rumors would no doubt spread unchecked anyway.
Much has been written, here and elsewhere, about backwards compatibility for gaming consoles, both with regards to the Xbox's successor, Xbox 360, and to consoles in general.
We asked our readers if backwards compatibility for the new Xbox was important; 43% of you said you wouldn't buy one if it wasn't, and only 17% of you thought it wasn't important or wouldn't affect their purchase decision.