The additional line should probably be:

application/msword; ns="%s"\; nf="${ns}".html\; /usr/bin/vw "${ns}" -o "${nf}"\;
netscape "file:${nf}" \; /bin/rm -f "${nf}"

Reassigning to powertools for package addition request...

added it to mailcap-2.1.1.

Also check that the temporary files in /tmp are properly deleted.
This also related to images which vw may create
if word document contains a picture.
(You may specify a directory to put temporary files).

Also last time I checked the command  
netscape "file:/tmp/filename.html"
the netscape was exiting right away, so the rm was deleting the file.
Do "shift-reload" in netscape just to make sure the file was not deleted
while in use (if it was deleted - you will get "document not found" error).

If you give me a link to 
your vw rpms and mailcap string I may send more comments.

Currently RedHat 6.2 already has a command like this, but for mswordview in
netscapes 'external helpers' configuration (*very* usefull).  In any case, it
deletes the files straight away, so a 'shift+reload' gets the 'document not
found'.

Its also worth noting that while the html file is deleted, the embedded images
(named after the file-name, but with further numerical suffixes) are not
deleted.  (Prehaps we should create a directory for all this to happen in, and
delete it when its all over - hopfully after netscape loads the images.)  

Sombody needs to keep an eye on /tmp races/games here too.

If the document is deleted right away
you will get a race on slow computers.
The document may be deleted BEFORE it was rendered.
You may add 
seep 600
to the end of command, so .html file will exist for at least 10 minutes.
Or, better option, replace netscape by somenthing better.
It crashes all the time and in many cases virtually unsuable.

A good idea may be to replace
"netscape" to
"gnome-help-browser"
in which case everything works OK.