Lots of Windows 10 news has been coming out lately, and a new technical preview build was also released yesterday.

http://blogs.windows.com/bloggingwindows/2015/03/18/windows-10-technical-preview-build-10041-now-available/

• Some of what's new:
• Improving the Start experience
• Improvements to Virtual Desktops
• Cortana is expanding into new markets on the desktop
• New network fly-out from the taskbar
• Enhancements to the Photos app
• New Text Input Canvas
• Experimenting with the Lock screen