In general, compared to a Macbook:
- It has a touchscreen
- It has a detachable keyboard
- It has a pen input
Microsoft's execution on the device is flawed. (IE, in order to use it as a laptop it needs a much more sturdy hinged keyboard,) but there's clear differentiators in their lineup.
IMO: Apple's lack of a touchscreen and detachable keyboard (or 270 degree fold) really hurts the Macbook lineup. If I could get a Macbook that I could also use as a table, or an iPad that truly ran OSX, I'd be happy.