Yep, we're already talking 10.1 already:
While Microsoft used the Windows Blue codename for Windows 8.1 and Threshold for Windows 10, the software giant is planning to use Redstone for its 2016 plans. Sources familiar with Microsoft’s plans tell The Verge that the company is planning two updates to the core of Windows in 2016, one in the summer and one in fall. These updates will largely be designed for new hardware and devices that run Windows, and will be targeted at the Xbox, Surface Hub, phones, HoloLens, Microsoft Band, Office, and other products that rely on the core of Windows. Redstone is the codename for the updates and a reference to Minecraft, the game Microsoft acquired last year. The Redstone name was first revealed by Neowin.