1. Aero Shake: Click a window pane and shake your mouse to minimize all other open windows. Shake the pane again to restore the windows to their original sizes.
2. Aero Themes and Aero Background: Use new themes or choose a slideshow of your favourite photos to make your PC reflect your personal taste.
3. BitLocker and BitLocker To Go: Help protect sensitive data with new, easier ways to protect and recover drives and extend that protection to USB removable storage devices, such as flash memory drives and portable hard disk drives.
4. Home Media Streaming: Use your PC as a hub and make music, videos, photos, and record TV available on other PCs or stream it to supported devices using Play To.
5. HomeGroup: Easily share files and printers between PCs running Windows that are connected to your home network.
6. Internet and digital TV: Watch Internet TV content and turn your PC into a digital video recorder by using the support in Windows Media Center for many new broadcast TV tuners. However, note that for certain aspects of Windows Media Center functionality, a TV tuner and additional hardware may be required.
7. Internet Explorer 8: Visual Search & Web Slices: Visual Search lets you see rich, relevant, visual suggestions as you type search terms. With Web Slices get the information you want from the Web updated and available at your fingertips, without leaving the page you are on.
8. Jump Lists: With Jump Lists, reduce clutter and quickly get to tasks and your favorite, recent and frequently used files.
9. Live Thumbnail Previews: Manage lots of open windows easily with live thumbnail previews of active windows.
10. Location aware printing: Set different default printers for your home and work networks.
11. Remote Media Streaming: Access your home-based digital media libraries over the Internet from another PC running Windows 7 outside the home.
12. Aero Snap: Resize and expand windows more quickly and easily compare the contents of two different windows.
13. View Available Network (VAN): See and connect to available networks -including Wi-Fi, broadband, dial-up and virtual network (VPN) – in just a few clicks.
14. VPN Reconnect: Get consistent VPN connectivity by automatically re-establishing a VPN connection whenever the Internet connection is temporarily lost.
15. Windows Search and Libraries: Search your own PC and the PCs and devices connected to your network to find items regardless of where they are stored.
16. Windows Touch: Interact with your PC with a touch-screen monitor by using your fingers and multi-touch gestures.
17. Windows Troubleshooting: Windows troubleshooting helps you resolve common issues quickly without having to call for help.
18. Windows XP Mode: Run many older Windows XP productivity applications right on your Windows 7 desktop.
19. AppLocker: Control which applications are allowed to run on user PCs.
20. BranchCache: Improve application responsiveness and end user productivity at branch offices while reducing the load on your Wide Area Network (WAN).
21. DirectAccess: Enable workers to more securely connect to corporate networks over any Internet connection – without requiring the extra step of initiating a VPN connection.
22. Federated Search and Enterprise Search Scopes: Enable search engines, document repositories, Web applications, and proprietary data stores to be searched from Windows 7, without writing and deploying client code.
23. Problem Steps Recorder: Help your workers troubleshoot application failures by giving them the ability to reproduce and record their experiences and then send that information to support staff. Know more about Problems Steps Recorder by going through our how to use Problem Steps Recorder in Windows 7 guide.
24. VHD Boot: Ease the transition between virtual and physical environments by reusing the same master image within a VDI infrastructure and on physical PCs.
25. Windows PowerShell 2.0: Automate repetitive tasks with this graphical scripting editor that helps you write scripts that access underlying technologies.
(via Into Windows)