Sholazar Basin is Northrend's Un'goro Crater, and has a pleasing mix of the familiar and the unfamiliar. A testing grounds of sorts for the Titans, you run into a lot of unusual lifeforms here like the Oracles, a race of intelligent murloc-esque creatures who are at war with the Frenzyheart Tribe of Wolvar. This is also the new hunting ground of Hemet Nesingwary, and trust me when I say his quests aren't nearly as awful this time around.
Zul'Drak is the center of one of the last Troll Empires, home of the Drakkari Ice Trolls. Under heavy assault from the Scourge, the Drakkari Empire has pooled their resources and pulled back to their capital, using some rather desperate measures to ensure their survival. Your first major Argent Crusade quest hubs are in this zone, and our old friends of the Zandalar Tribe will be meeting up with us here as well.
Edit: As always, if you're trying to avoid any and all spoilers, these galleries are not for you. There are no heavy plot spoilers contained within, but there are some light ones. If you don't like spoilers, don't look.