The game's variation comes not in the quests, but in your character development. Yes, all the quests are exactly as you describe, either kill & collect drops, or escort.

But character development - from talent builds to gearing - differentiates the playstyle on those quests enough to provide variation and make it interesting. Rogues, hunters, warlocks, mages, warriors, etc. all do the same quests much differently than each other.

The higher your level, the more pronounced those differences become, as your character has talents, skills/spells, and gear that define its tactics and strategy. Check out forums.worldofwarcraft.com to see all the discussion on optimizing talent builds and gear, with the ultimate goal being to dominate PvP or Raid Progression.

As for the geography, if you want to see something non-orange or different, try a different race. Humans start in a forest near a moated keep, Dwarves and Gnomes start in a frozen wintry landscape near a Moria-like city built into a mountain, Night Elves start in gargantuan tree, Blood Elves in magical forest, Tauren on a grassy plane, etc. etc. Every ~10 levels you move onto a different geography.