Good news! Windows 10 might officially be signed off this week it seems, as today build 10176 from the th1 branch appeared on buildfeed, and appears to be one of the first candidates for RTM. RTM stands for "Release to Manufacturing", which generally implies the software is complete, but this time round with RTM, that doesn't necessarily ring true.
The Windows 10 RTM will be a build of Windows 10 that is stable and not buggy, it will be missing a number of features that will be coming in later builds of Windows 10 as that is simply the nature of WaaS (Windows as a Service). As Terry Myerson put it recently, "we will never be done" as the software will always be updated. So this time round RTM is just a milestone, a starting point for OEMs and consumers if you will.
If all goes well, Microsoft could have an RTM build of Windows 10 ready by the end of the week, which is very exciting.
If you are unaware how the sign off process works, Microsoft will compile a number of builds they consider 'worthy' of RTM, these are called RTM candidates. These builds will be tested, and if the builds are found to have no bugs or issues, will be then voted on by employees. The build which is voted for the most is then selected as the RTM build, and recompiled into the winmain branch. The build number then usually jumps to a number which is divisible by 16 and 100, like 10400.
WinBeta is able to confirm that build 10176 from the th1 branch is indeed an RTM candidate. For those interested, the build in question is 10.0.10176.16384.th1.150705-0552. Microsoft appears to have jumped about 10 builds from 10166 to 10176 for its first RTM candidate. It's going to be an interesting week regarding Windows 10, so stay tuned at WinBeta for more news.Further reading: Microsoft, Windows 10