So Windows Phone 8.1 got released through the Preview for Developers app yesterday morning, and it is pretty awesome.
If you want it, first make sure that your device is in English (United States) for language and United States for region, etc. (This is primarily to ensure Cortana shows up as it's US only while the localization gets worked on.)
Go here, and select an option:
http://dev.windowsphone.com/en-us/develop/devpreview
I chose "
Register as a developer with App Studio" because it's fast and free. Use the account tied to your WP handset.
Once that's done, you'll need to download the Preview for Developers app from the App Store:
http://www.windowsphone.com/en-us/st...c-038393741e96
Install, go through the screens, check the box to opt-in for the preview, and go check for updates. You'll get two of them... one is a precursor to the WP8.1 update, and the one is WP8.1 itself. Install time depends on how much media and stuff you have downloaded to your handset.
Some users with HTC 8X handsets are reporting an issue where Cortana won't show up even with all the language settings changed... best way to avoid this is to make sure every single setting on your phone is set to English (United States) or United States, where applicable.