Also, I can't help but think that Microsft will take the whole "homogenization" of platforms between mouse-driven PC, touch-driven tablet, and phones, a little too far. Some form factors do need optimized UI's and code for that form factor or device type. You can't just use a one-size-fits-all for everything. It would be like Google using the phone UI for Google TV. It would be a mess.
I can see how:
Developers! can use NET and Visual Studio from the compact framework on phones via Silverlight, right on up to Windows Server at your DataCenter.
Developers! get a continuous stack.
Developers! can integrate everything from an ATM to a Website.
[edits: formatting, add quote to which I was responding.]
I'm asking because IntelliJ IDEA and Java do and I'm not leaving my POSIX toolchain for Visual Studio, no matter how awesome it is.
If you want a "continuous stack" there's nothing better than Java. And yet many developers still hate it, while many love the extremely limited iOS platform, which goes to show that this trait is not so important as one might think.
Close integration with the OS is not one of them.
Standard graphics libraries which meet contemporary expectations is also unfortunately missing.
There's nothing wrong with Java as a development environment, but the cost of "getting Java on the phone" is at best comparable to support for Windows (and at worst you're dealing with Oracle).
We're at the point now, where OS and language should merge. There should be a user data-centric design, with abstractions for the underlying hardware, so that most applications can be written across all of a user's devices, with "skins" for different particular form factors.
JavaFX 2, with rumored support for iOS and Android (likely WP8 if it has native code)
And it is unlikely that WP8 will have a JVM.
And iOS doesn't have a CLI VM but it still runs C#. Same thing for WP8, JVM can be packed with the app and AOT compiled to native code, maybe even JIT-ed if WP8 kernel allows it.
I suspect there isn't any easy solution to this one- same as there's no easy way to make OS X/iOS apps without running OS X yourself.
This means you can dock your Win 8 x86 tablet with a keyboard/mouse and be using the power of full Windows. You can write code for the tablet and debug it from the very same tablet using Visual Studio. You can't really do that with iPads and Android tablets which are relegated to being consumption devices only.
http://www.touchdevelop.com/help/api
There appears to be a vision of a commodity phone running Windows Phone as the "computer on every desk" for the developing world - it's probably no accident that Microsoft teamed up with Nokia.
If I can make a Metro app for Windows 8 and hit all desktop and Win8-tablet users and get WP8 users for free or very little cost... I see the number of applications for Windows Phone increasing very quickly compared to their slow start thus far.