Office 2007

I've been using it for a few weeks now - it's ok. Mostly a change in menu and tool bars. They have something they now call the ribbon which replaces most of those functions. There really isn't a lot of major invative things one can do with office apps - they have added a few nice suppliments, bells, and whistles to the various apps but nothing earth-shaking. You aren't missing anything if you have a fairly recent version of office, but you won't really find it all that different if you do upgrade either.
All in all, it's got a slightly different look and feel, but office is pretty much office and you'll probably like the new version once you get past the new look and layout.