An extensive re-education awaits those who will upgrade to the new Office 2007. It's truly a redesign. The menu bar and navigation buttons for Word, Excel and PowerPoint, for example, look completely different.

But before buying, I'd suggest you do think about whether you're willing to spend the time learning new ways of doing things. Office 2007 has a great many new features and controls.

There's something else that's very different: Microsoft uses a different format to save files with Office 2007 that, without a special viewer that will have to be downloaded, makes them unreadable with earlier versions. When saving a document with Office 2007, you have the option of saving as a previous version — which makes them compatible with earlier versions — but I'm betting this change alone is going to cause massive amounts of confusion among the early adapters.

That said, the beta of Office 2007 that I've been testing for the past couple of weeks is faster, more powerful and lots more intuitive and interconnected to other programs and files. Once you figure it out.

There are lots of subtle new features, too, like built-in blogging functionality and something called the ribbon that replaces the traditional toolbar and gives greater control over each program's various functions.

Office 2007 is the biggest change Microsoft has ever made to the interconnected suite of software tools so many of us depend upon.

So big, it's going to take a learning curve to master.

Buying Office 2007 also promises to be confusing. There will be no fewer than eight versions to choose from, all aimed at different markets ranging from home and student users, to small businesses, midsized companies and corporate conglomerates. Depending on what software you have bundled into Office, the prices will range from $147 to $679.