Similar to the Developer Preview or Consumer Preview of Windows 8, Microsoft is rumored to offer a public preview build of Windows 9 sometime between Q2 or Q3 of 2015 (around February or March of 2015) - giving consumers a chance to play with the new operating system before it's official release. Windows Phone 9 preview is also expected around the same time frame.
These details came from a leaked image (although censored), which we brought to everyone's attention on May 15th. The information originally came from a leaker by the name of "Faikee," who was recently responsible for dropping the Windows 365 name, along with other tidbits. Now, the image has been exposed in its entirety for everyone to see, revealing a few tidbits - most of which were already known up to this point.
Windows 9 is expected to feature some sort of changes to the Metro UI, Windows Defender, OneDrive, and Windows activation. Perhaps we might even see Cortana in Windows 9. No details on Windows Phone 9 were revealed in the image, aside from the preview release date. The image also hints that we can see the touch-optimized Office Gemini sometime this summer.
Take this bit of information with a huge grain of salt and remember it is just a rumor until Microsoft officially reveals any information. If you are curious, you can view the image at the VIA link below.