Definitely going to play a DK, have played one before, actually enjoyed some PvP during BfA because of my DK, but interested to see them in their full release splendor. Have an Orc Warlock at 11 that I'll probably keep playing offhand if my Pally starts to feel stale. Leveled a handful of classes to 10'ish before settling on the Pally, so have a few things I can pick up and tinker with, but Warlock and Pally were the first 2 that really jumped out at me. If I hadn't leveled a Warrior twice already, probably would have went that route. I won't play a Hunter again for a bit, pretty much main'd one the vast majority of my time playing WoW, so want to change it up.
Rogue and Priest are the only other classes I've never played really, so will role one of each if I stay interested long enough, or will be what I try out the next time I randomly decide to play WoW.