Don't you think WoW being run by a "remote mouse" and "remote keyboard"... I think the warden may call that a Bot...
The warden does not call anything by any name. The warden may detect software running, but it is up to human Blizzard employees to interpret this.

To make a long story short: there is no sensible reason to classifly MultiBoxing as botting per se.

Let me illustrate by pointing out the differences:

Botting:
A farmer starts the computers he is running clients on and logs his farming huntards in. He moves them to where they are supposed to farm. Then he fires up his botting program to run these chracters in a patrol-kill-loot loop. In the meantime the bot shepherd can go and have a smoke, or more likely in a gold farming sweatshop, fire up some more bots. Most of the time there is ZERO human attention or decision making involved. The characters are being played by a computer program. If a GM asks 'Hello Mr Farmer are you there?', even if the farmer comes up with some kind of audible alarm he will most likely be too late finding out which bot in the farm caused it.

Multiboxing:
A MultiBoxer logs in his charcters and moves them about. Every time one of the characters moves a step, /waves or does anything at all it is because the MultiBoxer has decided to push a button or click something. If the MultiBoxer takes a biobreak or goes for a smoke, his chars are just standing there - or are maybe flying somewhere on the public gryphon, but they sure as hell wont be killing or looting anything. If a GM or anyone else for that matter whispers a MultiBoxer while the character is doing anything at all, there can be an immediate response, because a human player is in control the entire time.

Wether that control is being excercised by a cabled keyboard, a wireless keyboard, a keyboard connected via a KVM switch or a remote assistance session or whatever else is not the crucial point.

Hope this helps.