I think assigning new models to things will probably come later, though the rest of the team is free to correct me on that. Maybe someone has already begun work, though with things in so much flux I'd be a bit surprised.
But yes, there are TONS of new models to work with, and I know one of the things we talked about early on was what those models could bring to the table. The additional differentiation will indeed be welcome.
At some point, once we get a few more features rolled in, I'll sneak some pics of some of the new models. It should be noted that it's not just items - MOBs also are much more diverse! But changing everything in the current world to make use of this new content is also a pretty substantial task, one that I'm fairly certain will occur later in the 3.0 cycle.