Let's cut through the gripes. Office 11 is scheduled to be released on or about June 30, 2003. And also on June 30, Win98 and NT will officially reach "end of life"--Microsoft will no longer support them. This is not a revelation: We've known about the 98/NT EOL for months. Cynics will claim such doings are to boost Microsoft's upgrade sales, but backward compatibility comes at a cost, usually in speed, stability or security. If Microsoft isn't supporting Win98, it stands to reason that Office shouldn't run on that OS.
Even so, you must be conscious of old OSs and versions of Office used outside your organization. Not all your business contacts will upgrade from Win98. Microsoft hasn't changed the file formats for a few years. If Office 11 has the same default file format, all is well. But if Office 11 uses a different or partially modified format, there will be trouble. The best bet is to use the lowest common denominator. Formats such as plain text and rich text are universally accessible and readable on almost any platform. Office 11 also includes an XML-based file format, which means the Office format might finally be fully open and readable without Microsoft software. But I'll believe that when I see it.