The official release date is tomorrow (June 24th) but that is not when most phones will receive it. It will be rolled out officially once manufacturers release firmware updates and carriers approve them. This process will likely take 2-3 months for all eligible phones to get the updates. The Lumia 930 was supposed to be released on this date but it appears it may be a couple of weeks late. However, the Lumia 630 and 635 have been released a few weeks ago and already include Windows Phone 8.1.