It’s true that finding people and objectives during quests can be exciting sometimes but for the most part, wandering around for hours to find a person you need to speak to for a trivial matter can get annoying.
Previously, if a quest required you to meet someone, there wasn’t any particular marker, which could tell you the exact person you should meet. So you would wander here and there for sometime until you finally spot the person.
Some Addons did facilitate the target exploration but now in Mists of Pandaria; Blizzard has taken notice of the matter and has introduced a new icon (a yellow word balloon) that will pop-up over the head of the people you need to meet or talk to. The icon is quite distinct can easily be differentiated from other quest markers. Quest targets will also be marked with white balloon marker on your mini map.
And if spotting the interactive objects was a troubling task for you, look for the floating yellow gear icons to track them. Overall, both the icons will make the exploration during various quests friendlier than before.