That timeline jibes with Riggs' presentation, as 1607 will reach CBB a year after the former build, 1511, landed on the CB.
Meanwhile, this summer's 1607 build -- which Microsoft has been calling "Anniversary Update" -- would be supported with patches on the CBB track until January 2018.
It's actually a bit less bewildering than Microsoft's original timetable for Windows 10, which was to sport three feature upgrades annually, and so have even more builds active at any one time.
There will still be multiple CBB editions active simultaneously, however. Riggs' timeline signaled an overlap between November 2016 and June 2017 when both 1511 and 1607 would be supported with security fixes. If Microsoft were to repeat its upgrade tempo of 2015 this year -- one in July, a second in November -- a smaller window between March 2017 and June 2017 would include three supported builds on the CBB, the latest stamped "1611" to mark its launch date.
The latter seems unlikely.
Speculation has been widespread that Microsoft will only issue one Windows 10 upgrade in 2016, then ship the next in the spring of 2017.
In Riggs' presentation, the word "targeting" in the phrase "Targeting twice per year..." suggested as much; it implied that Microsoft would shoot for two annual upgrades but might not always meet the goal.
The slower Windows 10 upgrade tempo is not completely unexpected. Two months ago, Gartner analyst Steve Kleynhans pointed out that the schedule was in flux, most likely because Microsoft realized it could not meet the original 3x pace, or that corporate customers were balking at a three-time-a-year cadence, or a combination of the two.
At the time, Kleynhans said that if a slower schedule were adopted, "It's because that's what the market has ended up telling Microsoft."
From what Microsoft told partners at WinHEC, it sounds like that market has spoken.
The "Windows as a Service" presentation that Riggs presented at WinHEC can be downloaded from Microsoft's website.
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