There's concept art for 5e Forgotten Realms up. Some people don't like it. I think it's way better than the stuff from 4e. They tried too hard to make the art in the 4e books all the same style, the same world, everything had to adhere dogmatically to the new D&D canon. comments here mention that the hobbits especially look like they're from Pixar. I'm fine with that. What I like about art in the older editions of D&D books is that they let individual artists express different styles: Easley does not look like Elmore does not look like Trampier, but it's all D&D. This 5e stuff is a tiny baby step back in that direction. Yeah, the hobbits are Pixar-ish, the humans could easily be from Game of Thrones and some of the monsters could have come from Peter Jackson (that Aboleth is bad ass) and I think that's great. I wish they would take this farther and let people really play with what D&D can look like.
so here's my beginning of a list of people who I wish WotC would hire to do D&D art
(but they probably won't):
Shawn Cheng, Zak S and some other folks
John Paul Leon
frickin Scrap Princess
This list can and should be added to. Feel free to make suggestions!