There will be three "branches": Consumer, Current & LTS.
Jan 2015, Terry Myerson of Microsoft, http://blogs.windows.com/business/2015/01/30/windows-10-for-...
"With Windows 10, the experience will evolve and get even better over time. We’ll deliver new features when they’re ready, not waiting for the next major release. We think of Windows as a Service – in fact, one could reasonably think of Windows in the next couple of years as one of the largest Internet services on the planet.
And just like any Internet service, the idea of asking “What version are you on?” will cease to make sense – which is great news for our Windows developers... Many consumers today expect their devices to receive ongoing feature updates without having to take an action. However, we understand that businesses require more control in how updates are delivered, and at what pace.
For example, systems powering hospital emergency rooms, air traffic control towers, financial trading systems, factory floors, just to name a few, may need very strict change management policies, for prolonged periods of time. To support Windows 10 devices in these mission critical customer environments we will provide Long Term Servicing branches at the appropriate time intervals.
... we are introducing a new approach for business customers, which we are referring to as the Current branch for Business. By putting devices on the Current branch for Business, enterprises will be able to receive feature updates after their quality and application compatibility has been assessed in the consumer market, while continuing to receive security updates on a regular basis."
Feb 2015, analysis of Jim Alcove (MS) blog post, http://blogs.windows.com/business/2015/01/30/windows-10-for-... & http://www.computerworld.com/article/2877983/microsoft-talks...
"Rather than rely on its decades-old practice of rolling out a new operating system every three years, Microsoft will stick with Windows 10 for much, much longer, updating the software on a frequent schedule with not only security fixes -- offered monthly since 2003 -- but also new features, new functionality and UI (user interface) and UX (user experience) changes and improvements.
The revamp, which experts have called Microsoft's biggest-ever change to its update and upgrade process, is integral to the firm's "Windows as a service" strategy."