Doesn't anybody want an Xbox 360 Core?
Our own poll here shows that even people who don't want an Xbox 360 outnumber those who want a Core. It's understandable; hardcore Halo fans want to play their old Halo games on the Xbox, and that requires a hard drive.
In all seriousness, does anybody want a Core? Microsoft isn't even offering it in the Japanese market, where the old Xbox did very poorly, and so backwards compatibility is a non-issue. Xbox360News is reporting that the US may have upwards of a million Xbox 360 units for the launch date, but that a mere 20% of those are Cores.
Are even those going to be sold, except to people pissed off that they can't find a full-fledged Xbox 360, but are willing to add the HD and wireless controller later just for the privilege of getting their hands on the console immediately? If the percentage of Cores shipped was actually higher, I'd suspect a massive bait and switch maneuver was underway.