Microsoft released Windows 10 for PCs build 15061 to the Fast ring, which is the third Insider Preview in the ring so far this week. The first was 15058, which showed up on Tuesday, and then we got 15060 just yesterday. All three of these builds are PC-only, so we're still waiting on something for Windows 10 Mobile, for which Dona Sarkar says the team is "tracking down a bug".
The company usually introduces new builds to the Fast ring on a weekly basis; however, it's crunch time. Rumor has it that the Creators Update is going to roll out to the public in less than a month, and Microsoft is already finalizing it this week, which means that Insiders could see an RTM as early as next week.
While Microsoft has said that PCs will get the Creators Update first and other platforms will get it later, that still doesn't explain the lack of a Windows 10 Mobile build. After all, while there will likely be some cumulative updates between when PCs get it and when phones do, the RTM build should ship to Insiders at the same time.
The Creators Update will include a number of new features, which focus on gaming, Edge, Windows Ink, Cortana, and more. Of course, there is also a number of features that will be removed or deprecated, as is the case with every feature update, which are anything from Flash autorun in Edge to Apps Corner.
As has been the case for a few weeks now, today's Insider Preview build doesn't contain any new front-facing features; instead, it focuses on making the necessary fixes in preparation for the launch of the Creators Update.