Antoine Leblond has a quick summary of new features in Windows 8.1 (aka Windows Blue): Continuing the Windows 8 vision with Windows 8.1. Here are a few fun new features.
The Search charm will provide global search results powered by Bing in a rich, simple-to-read, aggregated view of many content sources (the web, apps, files, SkyDrive, actions you can take) to provide the best “answer” for your query. We think this will really change the way you interact with the Web and with windows making it quicker and easier to get things done.
When you log on to your Windows 8.1 device with your Microsoft account (Outlook.com by default), your device magically becomes personalized with your settings and apps, making switching or setting up a new device really easy.
Variable, continuous size of snap views. You will have more ways to see multiple apps on the screen at the same time. You can resize apps to any size you want, share the screen between two apps, or have up to three apps on each screen if you have multiple displays connected, you can have different Windows Store apps running on all the displays at the same time and the Start Screen can stay open on one monitor. This makes multi-tasking even easier. Also in Windows 8.1, you can have multiple windows of the same app snapped together – such as two Internet Explorer windows.
Many more features are on the way. ^^