Office 15 is now only available as a Technical Preview to a limited number of beta testers, but Thurrot got his hands on it, and gives it a brief review. He installed it on a tablet running the Windows 8 Consumer Preview.
He found plenty of Metro-like features, noting that Word has "a full screen experience that indeed mimics some Metro-style design." He also found the installation somewhat problematic, and had issues with a clean install. Instead, he upgraded from an existing vesion of Office 2010 Professional. Even then, though, there were minor issues, notably the installation installing 19 separate live tiles in Metro.
The Ribbon is still there, but minimized by default, "helping create that clean, Metro-style minimalist look." Office 15 clearly is being designed with tablets in mind, because it has a new full-screen mode optimized for tablets, as well as being able to put into "touch mode," he reports.
Particularly notable is that Office integrates with the cloud and cloud-based services, such as Hotmail and SkyDrive. Thurrott was able to save a file directly to SkyDrive and work with it from there. It's not clear, though, whether Office will also automatically sync data from SkyDrive with your local devices and other devices. My guess is that eventually it will sync. The integration with the cloud may well be one of the Office's best new features.
Although I haven't gotten my hands on Office 15 yet, from his description it sounds as if much of the design is being optimized for tablets rather than traditional computers. If true, that's problematic. The vast majority of people will be using Office on traditional computers, not tablets, for many years to come and possibly always. Making Office more Metro-like is unlikely to make people more productive on traditional computers.
As I've written before, I think Microsoft is making a mistake by designing Windows 8 for tablets rather than for PCs. I hope the company doesn't make the same mistake with Office.