If you had chosen to handcode
Son of Suckerfish menus instead of using MM inline javascript it would be as simple as adding cursor: hand; to the stylesheet on menu hovers. It would also make your pages load faster since the code would be MUCH slimmer than using the old macromedia default dropdown code. One caveat is that cursor: hand; doesn't validate, if I remember correctly.
There's probably a way to add it to the javascript, but I'll be the first to admit that's not my expertise.