My WoW characters are amazingly skilled; without any training, they can instantly kill enemies, cast spells they've never seen before, learn how to make complicated devices, potions, poisons and bandages... and I only need to press a few buttons to make this happen. In different games, I have to do a lot of this myself; in FPS games, for example, I have to choose my weapon, aim, shoot, jump and run -- all as part of normal combat. In MUDs, learning a spell takes time and effort, and I get it wrong a few times before I correctly cast it the first time.
This article on GamerGod points out that our avatars in MMOs are increasingly handling more of the "tedious" side of gameplay, as decided by developers, leaving the more interesting parts for players. However, it's not all perfect, and there are some parts of gameplay that become tedious simply because they are abstracted into "click this button, go AFK". One of my favourite tradeskill quests in WoW is the Artisan First Aid quest, which requires a modicum of skill and is a lot of fun--when you receive Artisan level First Aid you really feel you deserve it.
The gathering professions do take the hands-on approach, as you have to scout out the materials yourself, but the other professions are based more on button-clicking. It's hard to please everyone, though; mini-games or mini-quests to learn new skills may work well (imagine taking WoW with you as a mobile game so you could train up your Engineering by playing a Tetris clone on the bus) but add another time-sink into the game which would put many players off.
Do you like the way the tradeskill system is handled in WoW, or would you prefer a more involved approach?