Pros:
 - 100% WCAG, ADA, and screen reader accessible.
 - No more script errors in older browsers.
 - Full keyboard access to each of the sub-menus (tab and shift+tab).
 - If we decide to use scalable font-sizes they can be implemented via a change to one CSS file.
 - If we decide to redesign the site, the DHTML menus can still be used without any change to the JavaScript.
 - Forward compatible with *every future browser* supporting DOM Level 1 and CSS Level 2.
 - Semantic HTML reads as a navigation list even in older browsers like Netscape 3, IE3, Lynx, and Mosaic 1.0.
 - Navigation is made up of real links so user gets standard UI feedback:
    - URL in the status bar. I can even update this to be the link text, category level, or a combination of the two.
    - Cursor feedback on every platform. Currently IE is the only browser that gets a standard link cursor (pointing hand). 
 - Superior maintainablility and smaller file size for scripts. This will require only one external script file to maintain. We currently have three, and all are individually larger in file size than this one.
 - While the file size for the cascading links may be slightly larger, the added speed in render time and smaller size of the includes will more than make up the difference. Also, the additional code makes the navigation more accessible in older browsers.
 - Cascading menus now work in Opera.

Cons:
 - Page size may be slightly larger just for the nav, though see the pros related to that above.
 - Limited style and no cascade functionality in Netscape 4 and IE4 (non-standards-compliant browsers).
 - Appearance minutely different in WinIE 5.0 (fine in 5.5 ad 6.0).
 - If menus are extra long, they /could/ move off the bottom of the page. This does not make them inaccessible b/c you can still tab or scroll to the items.