To be fair I have nothing more to add to OWG's quote, he is bang on the money, an excellent bit of advise, follow it.
Additionally at the very least 301 catagory urls to new catagory urls products change so map them to the parent catagory unless you have well ranked individual products in which case map url to url.
The sell to your boss is an easy one and it goes something like this.
"Look mate I can spend a couple of days doing these 301's to let google know where it should look for our products / service or I can spend the next three months resubmitting site maps and praying getting back a top position again, its your call do you want any online business or is the company making enough to do without google?"
Stitch in time saves 9.
So if you dont get fired you will probably do the 301's which is THE thing to do when you change a site IMHO.
Jez
p.s. disclaimer, if you speak to your boss like the above you will probably be fired or promoted, obviously edit the content according to how comfortable you feel
