I thought I 'd share some info from the Partner info document - NB: I have edited it as it was released as Confidential.

Partner Q&A
The new servicing approach for Windows 10 makes it easier for customers to stay current and get the latest features, while at the same time allowing them to pick the speed of innovation that is right for each segment of their users – rather than apply a one size fits all solution.

If your customer is running Windows 7 help them evaluate Windows 8.1 for touch scenarios today and plan for Windows 10 for non-touch devices. If the customer is evaluating, deploying or running Windows 8/8.1 then they should continue their work and upgrade to Windows 10 when available.

Q&A
Q: When will the next version of Windows be made generally available?
We look forward to the next version of Windows being generally available over the summer of 2015.
Q: Why did you choose the name Windows 10?
Windows 10 carries Windows forward into a new way of doing things. It is not an incremental change, but a new Windows that will empower the next billion users.
Q: Will Windows 10 be available for free to existing customers?
Microsoft has not shared any information about pricing at this time.
Q: If I buy a Windows device this holiday season, will it be upgradable?
It’s our intention that the vast majority of PCs and tablets bought this holiday will work great on Windows 10.
Q: Should I wait to buy a PC until the new version of Windows is out?
No, there are many great Windows devices in market for the holiday season. I’m especially excited about X and Y (insert
current products) which have Windows 8.1 Update.
Q: Should I download the Tech Preview?
Tech Preview is designed for PC experts who are comfortable downloading unfinished software, preferably on a secondary PC. This is not a developer preview designed for app compatibility testing. While we do expect many developers to
download the Preview, we fully expect them to run into compatibility bugs at this early stage.
Q: How can I download the Windows 10 Technical Preview?
Customers interested in downloading the Windows 10 Technical Preview, and participating in the Windows Insider
Program can visit Resources and Tools for IT Professionals | TechNet.
Q: What are the system requirements for the Windows 10 Technical Preview?
If you want to test the Windows 10 Technical Preview on your PC, here’s what it takes:

• Processor: 1 gigahertz (GHz) or faster
• RAM: 1 gigabyte (GB)
• Free hard disk space: 16 GB
• Graphics card: Microsoft DirectX 9 graphics device with WDDM driver
• A Microsoft account and Internet access

The Windows 10 Technical Preview can be installed on PCs meeting system requirements running Windows 7 or newer.
Q: Can I install the Windows 10 Tech Preview on a small form factor Windows tablet or a Windows Phone?
The Technical Preview is designed specifically for x86 based systems and is optimized for non-touch, mouse and keyboard
driven systems. Windows on ARM-based processors continues to be an important element of our strategy for phones and
tablets, and we’ll have more to share on the Windows experience for mobile devices at a later date.
Q: Is the Tech Preview compatible with earlier versions of Windows?
The Tech Preview will run applications designed for Windows 8 and Windows 7.
Q: When will the Tech Preview be available on a phone?
The date has not been announced.
Q: I’ve downloaded the Tech Preview and I’m having some trouble. Where do I go to get help?
If you’re having trouble with Tech Preview please visit Windows - Microsoft Community for assistance.
Q: Are partners expected to deliver updated device drivers and software for the Technical Preview?
No, not at this time. Microsoft will continue to keep partners updated on upcoming “Windows 10” milestones and next steps. Our intent is for the Technical Preview to work with existing drivers and partners are welcome to post updates if issues are found.

Seems this version is very much aimed at migrating Enterprises still running Windows 7.

A lot of testing of currenly deployed apps. I imagine would be the order of the day, rather than development testing as such.

Posted By: Superfly
01 Oct 2014