They were pretty illusion-y in 3.0, and judging by the list posted at http://enworld.cyberstreet.com/showthread.php?s=&threadid=53115&pagenumber=7 they don't appear to become less so. They lack some of the more combat-focused illusion spells (like Phantasmal Killer), but they do have things like the Image spells, Displacement, Invisibility, and so on.