"The good: Previously hard-to-find features now easier to explore; Word embraces basic desktop publishing tools; Excel formulas are easier to reference; PowerPoint presentations are more attractive; Outlook improves task and time management; improved integration throughout the applications; smaller application and file sizes; new file formats are easier to salvage if corrupted; document security is more straightforward.
The bad: Drastic design changes demand a steep learning curve if you're upgrading; new interface isn't always intuitive; contextual tabs and style galleries can be distracting; users of Office 2000 through 2003 must install converters to open Office 2007 files; no easy way to save work to the Web."
If you are using Office 2000 or 2003, and happy with it, there's no need to chase after this new version. But if you're in the market for an update from Office 97, or want to purchase individual components, focus on the 'good' as shown above, and conquer the bad by learning about the new features. Absent a way to save work to the web, you might also want a good web editing program. Let me know if you need help along the way.