Update: Microsoft's Julie Larson-Green further confirmed the news about Windows 'Blue' today, narrowing down a date for the OS' next milestone. A public preview of the next Windows is scheduled for release at this year's Build, Microsoft's annual conference scheduled to take place from June 26th to the 28th. The final release of Windows 8.1 is expected by the end of this year.

Rumors about what exactly Windows Blue will be have flown around the Internet for months and we already have a few ideas of what to expect. Now, thanks to a blog post from Microsoft interviewing Chief Marketing Officer and Chief Financial Officer Tami Reller, we finally have official confirmation that the codename refers to the next major update to Windows 8 shipping later this year.

Microsoft's ultimate goal with Windows Blue is getting the OS to run on a wider range of devices, which makes a great deal of sense with all of the rumors we've been hearing of the company planning to release a smaller version of Surface tablets. Reller specifically cites a "broad array of form factors of all sizes, display, battery life and performance" when she is referring to the changes in Windows Blue.

Windows Blue will also address some of the complaints from critics of the OS. Reller did not specifically talk about which criticisms the update would address, but simply said, "the Windows Blue update [is] an opportunity for us to respond to the customer feedback that we've been closely listening to since the launch of Windows 8 and Windows RT."

The interview also discussed Windows 8 apps, which Reller says have grown in number six-fold since the OS launched, noting that they have "already passed what iOS had in store, in its first year of app development." 

Speaking about Windows 8 adoption, Tami Reller revealed they've surpassed 100 million licenses sold, including licenses that ship on a new tablet or PC, as well as upgrades to Windows 8. In spite of it not being the boom Microsoft was expecting, the company is still happy with the performance overall. Reller rejects any notion of the PC being past its prime arguing it is "very much alive and increasingly mobile." 

At this point, it's difficult to say exactly what changes will come as part of Windows Blue. While Reller confirmed it will address customer feedback, she remained very vague about the specifics, particularly on the rumored return of the Start Button and a boot straight to desktop option. Other details including pricing, packaging and go-to-market details about Blue are expected to be revealed in the next couple of weeks.