I don't know why these articles, aimed at a relatively technical audience, usually concentrate on the iPad as a desktop replacement when they should be talking about Android.

Android allows you direct access to the filesystem, documents aren't locked to open in only one app, has processes to allow apps to interoperate, offers shells and compilers which allows coding in multiple languages, allows sideloading of applications, has mouse/touchpad support, monitor output (on tablets with hdmi out), and is generally not locked down to any noticeable degree.

I could almost use my Asus Transformer, with the keyboard dock, as a laptop replacement. If it would only offer window tiling so more than one app would show up at once, and if it had a more robust image editor, then I could probably make the switch full time. The 12 hour battery life would be a nice plus.