So first i saw this
Its a nice idea but it will probably never be suitable for World of Warcraft because of the complexity of all the abilitys.
And then i saw this http://www.bbc.co.uk/news/technology-12144231
If World of Warcraft is unsuitable for this, maybe something else would be? Maybe future MMO's will support this (Titan..?) i can imagine it being pretty successful if it was done right, imagine the ability to get all those Wii / Kinect players subscribing £8.99 a month to something as addictive as WoW...