As detailed by ZDNet's Mary Jo Foley, Microsoft's Windows Phone 8.1 Developer Preview was released for developers to test out before manufacturers release updates to existing devices. WPCentral provides specific instructions for you to get it on your device even if you have never developed an application, since Microsoft allows tech savvy folks to get the update along with developers.

I've captured screenshots showing some of the newest features of WP 8.1 Developer Preview as I have been testing it out on a Nokia Lumia Icon. I will post more of my thoughts as I spend more time with this over the next couple of weeks. In the meantime, make sure to read Mary Jo's take on using Windows Phone 8.1 DP .

Further reading

• Cortana: I want Microsoft's Windows Phone 8.1 developer bits
• Cortana blows away Siri and Google Now, may bring me back to Windows Phone
• Five reasons I am done with Windows Phone after 3.5 years
• Verizon Nokia Lumia Icon review: There's a new Windows Phone champ on the block
• AT&T Nokia Lumia 1520 review: Beast of a phone, but not the best
• Five reasons I dropped my iPhone 5 for a Nokia Lumia 1020
• AT&T Nokia Lumia 1020 review: The best Windows Phone ever made

You can select different background images and then see many of your Live Tiles change to show parts of the image. It's pretty slick how scrolling up on the Start screen scrolls through the full image even if some of your Live Tiles don't show the theme image.

Action Center is one of my favorite parts of the update and, unlike the failed iOS implementation, this one from Microsoft truly lets you take action on notifications and has deep support for applications.

I love that you can view past searches and Cortana commands in your notebook. Cortana truly is a personal assistant, beyond what we see in Siri and Google Now.

As a reviewer who tries out lots of phones, I love that I can now sync my settings and then have my theme, app settings, IE settings, and passwords synced across devices.

Reviewers take lots of screenshots and as you can see the button combo has changed in Windows Phone 8.1.