Chronicwire reports that the Gold Master build of iOS 5.1 has been in a “vigorous quality assurance phase” for the past three weeks” with testing being done both internally by Apple as well as by various carriers/partners.

As we first reported, it contains Japanese Siri as well as some features not previously revealed publicly  (Camera Slider?).

The build number of iOS 5.1 Gold Master is 9B176 according to a very solid source, although three different partners who are testing the Gold Master claim to have slightly (by single digits) higher builds numbers on their copies, I’m assuming that’s because right now it’d make sense for those people to be testing what will soon be released as 5.1.1, so I’ve disregarded the claims.

Chonicwire’s Will Strafach (@chronic) has been a good source of Apple’s iOS software info in the past.

We’ve been hearing whispers of expanded Siri integration (more devices and perhaps integration into the Remote App for AppleTV) but are a long way (well probably 24 hours) away from being able to verify.