Developers can download the new and supposedly very cool Windows Phone 8.1 Update.
Microsoft's Joe Belfiore just announced on Twitter that the highly anticipated Windows Phone 8.1 Update is available now to Developers. Microsoft unveiled Windows Phone 8.1 at the BUILD 2014. You can watch the Windows Phone 8.1 introduction in the video below highlighting what is new - and there is tons of new stuff, including Cortana. Cortana is Microsoft's Siri.
If you are not a developer you can get Windows Phone 8.1 as well right now. You are voiding though your phone warranty. According to The Verge you just need to do the following:
1)Go To Windows Phone App Studio site and sign in with your Microsoft Account and create a project. It is Free.
2)Download the special preview app on your Windows Phone 8.
3)Sign in to the app with your Microsoft Account to enable the phone to detect the 8.1 update.
4)Now your phone can be upgraded to Windows Phone 8.1