Just Installed it on Windows 8
Since I'm already running the Win8 90 day trial I didn't see any more risk installing this. After the install it popped up the initial word first time in a full screen mode and I thought 'Oh shit, it's going to act like a Metro app on Win 8!'. Luckily my first impression was wrong. It is a standard run of the mill program.
Now that said, I've not used Word 2007 or 2010 that much, so it's quite a bit different from the Open Office I use regularly. If you've used the more modern versions for daily work, I don't think it's that much different. The default color scheme is very pale (or bright white depending on your view), I opted to change its appearance (theme) to a dark grey so I could tell my work zone apart from the application.
Office is directly integrated in to a Windows Live account, and when clicking save, allows you to save directly in to a Skydrive (or to your own hard drive if you so choose). If your internet connection is flaky, clicking browse on the Skydrive can lock up the Office interface for quite a while. There is an option for "Add a Place' that gives the options for another skydrive or sharepoint, hopefully there will be a way to add a Google drive in the future if Microsoft lets us have a way. All this said, I'd like to know how Office behaves when I'm offline, and it would be nice to know what it is randomly sending back to the mothership.