I believe it is AUS6, but I can't check because my girlfriend lost the one I gave her...
Jesters are usually not meant to be used as a primary knife, so it should be fine. But even if it's going to be your primary knife or only knife, AUS6 should get the job done. There's a lot of hype about all the new and expensive steels. Sure they do take sharper edges, but not so much that it really matters to the average person. And sure they hold edges longer, but they also generally take longer to sharpen because they hold the edges that much longer. In any case, you'll have to sharpen again at some point. In both cases you'll generally have to at least touch up each frequently if the knife's being used constantly.
Point is, before new steels came out, people were generally happy with the performance of the steels that they had, as limited as they may seem today. I can imagine people in the coming years typing about how they "only have that model in S30V/ZDP/INFI/M4" when more popular steels take over the hype market. I don't know about everyone else but if I continued with the level of cutting chores that I do these days, from a purely utilitarian perspective , I really wouldn't "need" any new knives to replace what I already have- regardless of how much "better" steels get in the future.