At the moment what we know about Windows 9 is mostly rumor, but it is fairly reliable rumor. It seems that Microsoft has something to announce on September 30th and we can start to prepare for the changes.
Windows 8 has done desktop development a great disservice. It, plus Microsoft's de-emphasis of established technologies for the desktop and the web, have made it difficult to know what to use for new projects. Until Windows 8 the answer was usually that it was a good idea to go with whatever Microsoft proposed as the next big thing. But, with Windows Phone, Slate and Windows 8 itself not exactly securing enough of the market to be a sure bet, the new technologies on offer didn't look promising. What is worse is that while the desktop remains a big potential market, who wants to develop for Windows 7?
Also, with the withdrawal of desktop widgets from Windows 7 on, there has been no way to create small utilities for the desktop. You could create a modern app, but it can't be seen while in desktop mode. Try creating a web app for Windows desktop and you will have a hard time finding a simple, coherent, technology.
So as well as the missing Start button to allow developers to organize their programs into something that is easier to use, there are lots of problems with Window 8 and creating apps for it.
The result is that most developers are looking forward to the inevitable course corrections that Microsoft has to make to allow the train to start moving again. Most of what we know about the version of Windows codenamed Threshold comes from sources proven to be reliable in the past - mostly Znet's Mary Jo Foley.
While we can't rely on any of the proposed new features, it makes sense to have some idea of what they are, if only as an exercise to judge if Microsoft has passed or failed the test when it makes clear what it has waiting on the Threshold.
So far the list of rumored changes include:
A new Start menu that carries a mix of Modern and old fashioned desktop apps. This is good as there was never any compelling reason to place an iron curtain between Modern and old fashioned and between Modern and the desktop. Just doing this isn't enough, however. The new Start menu needs to be hierarchical like the original Start menu and it has to operate in a way that doesn't break the workflow, i.e. no switching away to a screen or display that means you can't see the multi-windowed desktop.
It also seems likely that tablets are going to get a version of Windows that doesn't include the desktop and that the Modern UI, i.e. the Start Screen, will be removed from desktop Windows along with the ridiculous Charm bar. This makes some sense and the ability to create Modern apps that run on tablets and the desktop is very attractive. There is absolutely no reason why tablets and desktops have to share an identical UI. What matters is that we can create apps for both using the same code.
The new Windows RT won't include the desktop and will run on tablets and Windows Phone. This is a sane move. Windows Phone may not be taking over the world, but having to craft code to run on it makes it even less attractive.
In the future we may not have this step change to a new version of Windows at all. The suggestion is that Microsoft is planning to make monthly updates to Windows in the style of Office 365. There may never be a Windows 10 and it is even conceivable, but unlikely, that there will never be an OS with the name Windows 9.
At this point the list of what might be raises lots of questions. Will Microsoft follow a subscription route for Windows 9? Will it give the core OS away and make it money on services? Will it offer a desktop upgrade to tablet users - but for a price?
One thing that is clear is that Microsoft cannot afford to get this one wrong. The future may be mobile and it may be the cloud, but there are still a lot of desktop machines running Windows XP/7 that could move to a better version of Windows should one become available. A version of Windows that gives the best of the old world and the new is what is really needed.
Look out for more information in September and a technical preview towards the end of September.