Just two days after releasing the second, Apple today released the third GM Candidate version of OS X Yosemite (build 14A388a) for developers.
The new version is available both on the Apple developer portal and the Mac App Store for those running the beta version of the system.
It is quite possible that the company will soon release the OS X Yosemite Beta 6 (build 14A388b) for users participating in the OS X Beta Program.
Apple has already confirmed a special event for 10/16 (Thursday of next week), when it will most likely launch new iPads, Macs and OS X Yosemite.
Update · 10/13/2014 s 14:34
It took a while, but OS X Yosemite Beta 6 is now available to users. More information in this post.