If you are a member of the Windows Insider program and have signed up to get preview builds of Windows 10 via the Fast ring, you should prepare to see more builds on a more rapid release schedule soon. Microsoft has revealed they plan to step up the pace for more Windows 10 builds for those members starting in January.
Microsoft's Gabriel Aul wrote today:
"The new criteria will be much closer to our criteria for flighting to our internal rings, which means more builds will pass it and be released externally to the Fast ring. This also means however that the builds we release to the Fast ring may include more bugs and other issues that could be slightly more painful for some people to live with. It's a tradeoff – as the thing that throttles the rate of builds is the promotion criteria."
While most Fast ring members will likely welcome this change, Aul recommends that Insider members who want more stable preview updates should switch over to the Slow ring update schedule.