> Existing use of Stage 0 (the first sector):
> 
> 	Offset	Size	Machine	Use
> 	------	----	-------	---
> 	0	512	i386	MBR boot sector

If you are going to to specify the i386 MBR magic number as a separate entry 
(and I think you should), then the rest of the i386 MBR should be broken down. 
My suggestion is

	0	var.	i386	MBR boot sector
	446	64	i386	MBR partition table

This helps show that there is space for the i386 MBR to co-exist (cohabit?) 
with other systems if the boot block author is cunning enough (and the fates 
are willing).

This is a great idea and I'm willing to help with the destr^Wtesting.

Cheers,
Lloyd