Hi,
jQuery doesn't really have menus or menu styling in the box yet. There may be something useful in jQueryUI 1.9, so maybe in the future I will look into it, but jQuery UI tabs for example should not be confused as being useful as a general purpose menu. A menu renders generally as a nested set of ul/li elements. jQuery tabs use markup that is not suitable for a menu, it is a self contained widget and the tabs do look like a menu, but the structure is nothing like what one would typically have for a menu. A menu is just a list of links but the tab widget has a list of links and a container div for each item and a paragraph for each item.
Best,
Joe