There are some nice leveling guides for those of us players who level blood elf paladins-jewelcrafters
nowdays.
E.g.
http://www.wow-pro.com/node/754
Any questing and grinding plan can be formulated as a sequence of simple tasks:
- move to location;
- accept quest;
- complete quest's objective;
- complete quest;
- gain level.
Are all these tasks trackable with API? If so it's possible to make a checklist addon that will be a huge time and nerve saving tool for anyone who is trying to level fast.
Each list point can have brief instructions what to do next and maybe some hints (like coordinates of quest NPCs and objects) for most complicated missions. This will allow "multitasking" of quests with repetitive objectives (collecting or smashing things on the way to some other quest's objective).
Time for switching from the game to guides and databases and nerves to keep plan in one's head are huge even for 1 leveling toon and there are millions of them!