You might try searching the MS site, they used to have a HTML lite module for Word that would leave out most of that style junk.

If you never look at the raw HTML and don't mind bloated files, the regular Save As will work fine.

Or, if you use Dreamweaver MX, it does have a fairly good built in Word stripper. Otherwise, as suggested, you'll have to get one of the other stand alone HTML strippers to clean the file up.