The Apple philosophy is to limit what devices can do, and Microsoft’s is to expand the things they can do. MS wants to be all things to all people. That’s hard to do.
But Job’s “total control” gave us such wonders as the one-button mouse, the keyboard with no cursor keys, cases you can’t open without special tools, and Big Brother oversite of what “apps” users are allowed to run.
The Surface has a lot of new technology that redefines how a table can be used. The iPad is for content consumers only. The Surface is clearly intended for content consumers and content creators. All things to all people.
I willing to bet in three years the iPad will look a lot more like the Surface than visa versa.