Microsoft's Chief Operating Officer (COO) Kevin Turner mentioned that the current plan is to release Windows 10 late summer or early fall 2015. Without getting into details Mr. Turner talked about how they have connected their different operating systems across desktop, phone, tablet, and internet of things via the same kernel. Does this mean that Windows 10 will be released to all devices late summer or early fall? This we don't know.
Windows 10 so far has been mostly experienced through the technical preview, however that will change in early 2015 because Microsoft plans to talk about their consumer plan. A consumer focused version of Windows 10 is expected to come with more refined animations, icons, continuum, and a couple of more features mainly focused on refining the UX.
In addition to refining the desktop version of Windows 10, Microsoft is expected to show off plans for their tablet and maybe phone variants. This is where Windows 10 will begin to look and feel like a new product because Microsoft is trying to create a clear divide between desktop and tablet environments. Currently Windows RT has a desktop which can run Explorer, Control Panel and the like, but with Windows 10 on the tablet is rumored to not include the desktop. However a lot of the details of their consumer plans are unknown and subject to change.