IMO, this is somewhat worrying.
MS haven't been able to put out a new update since b10130 (apparently due to bugs).
They only have ~4 weeks to fix the bugs and push the builds out for testing.
I'm surprised MS hasn't released a new build yet. For me build 10130 was one of the worst builds I installed. The leaked 10147 build is definitely the best build I've tried so far. When build 10147 was leaked I thought for sure a new build would be released in a day or two.
Some of you are calling it the "FINAL BUILD" when it goes to RTM.
Microsoft has already said this will be a rolling schedule so final build means nothing. Insider program is to continue and the software writers are going to continue to add and update Windows 10 as we move forward. There will be bug fixes and add on stuff comming all the way to the next big update planned around the new years. As you can see Windows 10 is going to be a fluid release with add ons and features added later.
It's easier to say "final build", than "the version that MS is planning to release to the general public".
IMO, all OS releases are effectively "rolling releases" (due to the number of updates they receive).
If W10 sells as well as the W8 series, you can bet MS will release a "new" version of Windows and call it something else.
It's final only when support for a version is stopped. Since Win 95. every, even major versions, were continuing from one to another, only the speed they evolved is changing.
Just hope it is not two fast, as a consumer I don't want a new build every month though. Maybe once a year. Updates are fine.