Update: Mobile build 10.0.14393.351 is now rolling out to Preview Ring. More here.
Original Story: Microsoft is now testing new cumulative update for Windows 10 1607 users. The upcoming update will push Windows 10 build to 14393.351. The new cumulative update build 14393.351 and mobile build 10.0.14393.351 is compiled on October 14, 2016. Today, the company also released update KB3199209 for Windows 10 1607.
Previously, Microsoft released cumulative update KB3194798 (Build 14393.321), KB3192441 (build 10586.633) and KB3192440 (Build 10240.17146) for Windows 10 users. Windows 10 preview build 14931 is also now available for Slow ring insiders. You can download ISO from here.