By request: Roy Batty.
Now that we are getting new character models (someday soon, I hope, perhaps on 6.0?), do you think we'll be getting every model (including Pandaren) included? We're talking mobs, bosses, and critters for every expansion. Do you think world models / textures will be included as well? (Trees, mountains, platforms in outlands, etc.)
No, absolutely not. The pandaren are brand new -- there's no way they'll receive an upgrade in the foreseeable future. As for the rest of the world, it's unlikely; there were some graphical updates to geography in Cataclysm, but that was also kind of the focus of Cataclysm. As much as I'd love a full graphical overhaul, it'll probably never happen. We'll have to be happy with the new race models. And definitely expect the first batch in 6.0.