I swear. I hope we get details of sites in the various planes. Not just 'here's an eladrin city' 'here's a Shadar-Kai fortress' 'Now, here's some stat blocks, paragon paths, feats, and we're done!"
In the Worlds and Monsters book, it described various places like the Fungul city where Troglodytes live, having tunneled through skyscraper-sized mushrooms. They donated a single paragraph to it.
Various tidbits that spark the imagination, fantastic sites, domains, etc. If you were writing a Tourist's Guide to the Plane, you'll only mention the cities as far as their nightlife, food, friendly customs and interesting sights. You'll spend more time blabbing about the cool rock formations, coral reefs, flora and fauna and the types of attractions a tourist would want to go and see. An adventurer is much like a tourist, but instead of wearing sandals and seeking pictures, he's wielding a sword and going to kick a door in.
And considering that the Planes are more Fantastic than the World, then they should have some wild stuff. Forests made of crystal, mountains made of flesh and bone, an iron honeycombed island amid a vertical maelstrom of water, crafted by the Storm Titan and his Lightning Archon armada.
I want places that grab me by my creative gland, shake me like leg bitten by a chihuahua, and say "I DARE YOU to bring your PCs here!"