All the gen IV reactors I remember are thorium based, however keep in mind that most of the gen IV reactors can be made with uranium, it's just that thorium is a rather nice fuel. Well, if you don't need to build any more nukes, that is.
To be perfectly honest, once you've mined out all of the nuclear materials out of nuclear waste, what you're left with is a fairly standard bundle of heavy metals that we deal with all the time in chemeng. (ie. what do you do to the Cad in Nicads?)
Anything that's fertile can be converted into fuel. Anything that's fissable is fuel. Anything that is usefully radioactive can be used either directly in a reactor or indirectly in betavoltaics and related.
One major problem at the moment is that it's not politically viable to reprocess waste anywhere near completely, and even though waste storage is basically solved in much the same way that the waste storage of garbase is basically solved (Where do you think the toxins go when you throw something else out?), we can't really do either and so you end up with waste just piling up in places where it honestly shouldn't be.