This is it! A nice summer surprise. The final build of Windows 10 will be available to upgrade to on July 10th. I'm pretty excited!
https://blogs.windows.com/bloggingwindows/2015/06/01/hello-world-windows-10-available-on-july-29/
https://blogs.windows.com/bloggingwindows/2015/06/01/hello-world-windows-10-available-on-july-29/