Drat, another update. I just updated my PW a couple of weeks ago after the previous firmware failed to update automatically over wifi. If I remember correctly it was a large (163 mb - just checked it's still in my recycle bin) file I had to download that time as well.
I noticed the link up on the Amazon UK Kindle discussions forum for this update appeared just this past day as well.
*added* update just finished downloading so off to get my KPW and complete update before I forget ... and I will if I wait.