At JP Morgan's Technology, Media & Telecom Conference, Microsoft's Windows Division CMO and CFO, Tami Reller, confirmed that the upcoming Windows 8 update, previously codenamed Windows Blue, has now been given the official release name Windows 8.1, and will be a free upgrade for all Windows 8 users.
The upgrade will be available from the home screen when it launches, while a preview version will be opened up to the public on 26th June at the beginning of Build 2013. Reller wasn't able to give an official release date for Windows 8.1, but stated that it will be "later in the calendar year." She also said, "we know when the holidays are" so expectations point to a release date around November or December.
Windows 8.1 will be available for both the full version of the OS as well as the ARM-friendly RT version.