[LeafyGreenbriar]

So this time next year we will have the Microsoft Surface 4, the Surface 4E (or some other letter that really means "the cheaper one" and comes in fun colors), the Surface 10.1, and the Surface 10.1 Professional Edition.

[Splognosticus]

You forgot Surface 10.1 Home and Student, which reserves the top quarter inch of the screen for a message reminding you that you're not allowed to use it for work.

[ConceptJunkie]

Don't forget the Surface Starter version that only lets you run 3 apps at once... wait, that would be a step up.