Windows Tablet Edition is not a Tablet OS. Android is not a Tablet OS.
Android could be defined as a "mobile device OS". It can run on devices that have screens ranging from ~3" to ~12".
There are two main factors when dealing with such small touch screen devices that forces developers to do major compromises in their interface design.
1. As you get closer to a palm sized screen, you quickly end up running out of space to put text, buttons and other interface elements that are big enough to be legible.
2. Unlike a cursor on a traditional OS, which symbolically has an infinitely small pointing size, fingers have a minimum average size. Fingers get in the way as you get near a palm sized screen.
The problem for Android is that there's no automagical way to gracefully scale touch screen interfaces for an optimized usage within this range of sizes.
Take a music player/manager program for example. On a small smart-phone screen, you simply can't seriously try to fit an iTunes-like interface on it.
If you look at the iPod interface on the iPhone OS, you see that it's essentially a big menu list with a few buttons on the top or bottom, which makes sense because of the scale of the screen and the fact that your finger takes like 1/5th of the screen width in portrait mode. And an high resolution screen doesn't save you from these limitations.
Now, imagine that you try to gradually scale your music/player toward supporting a bigger screen. At one point (maybe 6"?) you realize that you could have something that's more like iTunes by dividing your interface in two, with your sources in a list left, and your content list at the right. At another size, you realize you can afford to add a spectrum analyzer at the top of the interface.
How does a developer decide where is the crossing-point where he should make a source list menu appear? What if a developers thinks that the source column is so important that it should appear even on 4" devices even if it's barely usable? Maybe it can be togglable even if activating it on a 3,5" screen would be useless?
I don't see the general public being enthusiastic to have to fiddle with toggles to customize widgets and columns to enable an app to fit on their mid-size tablet device which happens to be somewhere in between an Android phone and a "full-size" tablet.
People will try to run apps designed with Android tablets in mind on a device that's just too small for them to be useable without any frustration, and on the other end, running apps designed for small screens on a 11" screen, ending up with wasted screen space, only a few overlarge buttons and limited functionality. This could end up in a mess of compromises.
Apple on the other hand will clearly define the Tablet OS as a different platform than the iPhone OS, even though they will share a lot in common. Developers won't have to compromise the interface one way or the other for "in-between" screen sizes. They'll be able to focus on maximizing the use of a 10" multi-touch screen (or whatever size the Apple tablet will be).
As such, the Tablet OS will define a new platform category on its own.
Edit: And Chrome OS isn't anything near a "Tablet OS" at this point and may never be...
Android could be defined as a "mobile device OS". It can run on devices that have screens ranging from ~3" to ~12".
There are two main factors when dealing with such small touch screen devices that forces developers to do major compromises in their interface design.
1. As you get closer to a palm sized screen, you quickly end up running out of space to put text, buttons and other interface elements that are big enough to be legible.
2. Unlike a cursor on a traditional OS, which symbolically has an infinitely small pointing size, fingers have a minimum average size. Fingers get in the way as you get near a palm sized screen.
The problem for Android is that there's no automagical way to gracefully scale touch screen interfaces for an optimized usage within this range of sizes.
Take a music player/manager program for example. On a small smart-phone screen, you simply can't seriously try to fit an iTunes-like interface on it.
If you look at the iPod interface on the iPhone OS, you see that it's essentially a big menu list with a few buttons on the top or bottom, which makes sense because of the scale of the screen and the fact that your finger takes like 1/5th of the screen width in portrait mode. And an high resolution screen doesn't save you from these limitations.
Now, imagine that you try to gradually scale your music/player toward supporting a bigger screen. At one point (maybe 6"?) you realize that you could have something that's more like iTunes by dividing your interface in two, with your sources in a list left, and your content list at the right. At another size, you realize you can afford to add a spectrum analyzer at the top of the interface.
How does a developer decide where is the crossing-point where he should make a source list menu appear? What if a developers thinks that the source column is so important that it should appear even on 4" devices even if it's barely usable? Maybe it can be togglable even if activating it on a 3,5" screen would be useless?
I don't see the general public being enthusiastic to have to fiddle with toggles to customize widgets and columns to enable an app to fit on their mid-size tablet device which happens to be somewhere in between an Android phone and a "full-size" tablet.
People will try to run apps designed with Android tablets in mind on a device that's just too small for them to be useable without any frustration, and on the other end, running apps designed for small screens on a 11" screen, ending up with wasted screen space, only a few overlarge buttons and limited functionality. This could end up in a mess of compromises.
Apple on the other hand will clearly define the Tablet OS as a different platform than the iPhone OS, even though they will share a lot in common. Developers won't have to compromise the interface one way or the other for "in-between" screen sizes. They'll be able to focus on maximizing the use of a 10" multi-touch screen (or whatever size the Apple tablet will be).
As such, the Tablet OS will define a new platform category on its own.
Edit: And Chrome OS isn't anything near a "Tablet OS" at this point and may never be...