‘it is clear that any Apple numbers claiming a 10% or greater market share are listing other devices (like the iPhone and its variants) as “computers,”’
Wrong, you should really do your homework before you embarrass yourself.
The 10% figure is for new PCs sold in the US. Your W7 numbers include copies to upgrade computers with earlier, inferior versions of Windows, and are worldwide to boot. ;-)
I made, over the course of this thread, more complete arguments about market share. Sales in the calendar year 2010 are just that. A true discussion of market share must include all actively used computers sold prior to 2010. It must also consider what machines were transferred or replaced as a result of the aforementioned sales.
Apple sold more than 10% of the computers in the U.S. in the third quarter of 2010. This does not mean they have 10% of the PC market share because market share is not defined by a three-month sales period. A computer is not considered a consumable device, so a quarterly sales report is of greatly reduced importance.