Posted something similar to this on the Xbox Team site, but due to corporate moderation it might never see the light of day.
In summary, it was a remark about the differences between this feature and the Xbox "reformat" feature (Settings/About/five digit "secret code" beginning with Y) that was specific to each console, and why they chose it over a generic implementation.
I haven't been following the Xbox scene lately, though - had anyone arrived at a definitive answer as to the original Xbox's "clear user partition" feature, and whether it was serial/kernel/dash specific?