Microsoft announced new universal office apps for Windows 10 previews during 21st January event. It even demoed a bit of new touch-optimized Universal Office apps for Windows 10 and then provided more info in a new blog post that also talks about new Universal Outlook mail and calendar app. The Windows 10 for Phones preview will bring the Office Universal apps suite to Widows Phone devices and it was supposed to be available for Windows 10 Technical preview in some time.
Good news is that the office apps are now available to download for Windows 10 Desktop (Technical Preview).
You can install the apps from below links.
Word Excel Powerpoint