I'm confused. Does this mean that TokyoPop is starting to do novel translations? "Manga novel" is a bizarre neologism that may mean "novel" or "picturebook" or "different binding class of manga". Hrm, the CLAMP offering is a "text novel". That would seem to indicate that we're talking actual novels, here. Though the CLAMP one sounds more like a novelization of a thoroughly unpopular and uninteresting CLAMP series; I suppose I ought to be happy it isn't Dukylon.
Slayers was initially a very popular series of fantasy novels; since there's a Slayers title in the initial offering, I think we can be fairly confident that these "manga novels" are translations with the occasional illustration for those that haven't quite grown out of the picturebook demographic.