Craig Bailey gives a great rundown of features to be found in the latest Office 2007 Technical Refresh.
I'm glad he did this because while he identifies the good, he also identifies the bad (Project 2007 being hosed, among others), the ugly (Visio Startup) and the just plain "huh".
I had the beta on my laptop and unfortunately, that box lives on gmail and the web mostly so I've only had to use it a few times. One thing I hope they have fixed is their backward compatibility with Word 2003. I'm still out as to whether I'll do a full upgrade or even recommend it. As Craig notes, when some features aren't "backwards compatible so you are limited in who you can send it to" - this will really limit to how much it gets used. Microsoft should spend the resources and put together a web-based or free download tool to allow viewing of these files as they used to do. (if one already exists, then I've missed it)