Thanks Tony,
If it helps, it looks as if on the current version of the editor (as found at http://cutesoft.net/example/general.asp), the Paste from Word button exhibits the new behaviour, but the "Clean up HTML" -> "Remove all word specific markup" action still exhibits the old.
As far as I can see, all the functions required to get fairly clean code out of Word are present: New Paste from Word, followed by "Clean up cascading style sheets", then "Clean up <Span> tags".
What we really need is a Button and Ctrl-V preset which will do all of these actions at once, without requiring users to jump through hoops. Perhaps an option could be added to control how Paste from Word works - either "Cautious" mode, which leaves all valid HTML in place, or "Aggressive" mode, which also performs a cascading style sheets cleanup, font tag cleanup and span tag cleanup afterwards.
If you're copying in from a Word document, then the chances that you actually want all the extra <span>s and style stuff that Word adds are pretty low, so I imagine the Aggresive style clean would be far more useful.
Dave