ZD Net's Mary Jo Foley heard from her sources that Redstone is on track for a launch sometime in Summer/Fall 2016 and that Redstone will likely still be Windows 10. Microsoft isn't planning to launch this update as Windows 11 but perhaps something like Windows 10.1 isn't out of the question.
The update will be distributed to Windows 10 users as part of the monthly update cycle but it will be significantly larger than the usual updates. Redstone will add new functionality, including features that were cut from Windows 10, and add support for "new classes of devices that aren't already part of Windows 10."
Releasing regular updates to Windows 10 works well for things like Spartan (the new Windows 10 browser), messaging and the Start Menu -- things that increasingly are not part of the Windows core. But for deeper core work to support the devices building on top of Windows 10 -- things like Xbox Surface Hub, Windows Phone, and HoloLens -- sometimes bigger changes are needed that require bigger updates like Redstone.Foley also heard rumors that the Windows Insiders program will continue to be an ongoing thing, meaning people will be able to test these larger updates before the public launch.
My sources say the Windows Insiders program will continue throughout the Threshold/Redstone development/delivery/deployment timeframe, meaning Microsoft will continue to provide early test builds of not just the monthly updates, but the larger updates to Windows 10, too, into next year, and possibly beyond.