In any case, the only theoretical possibility that a judge might consider refers to misleading publicity, if it is proven beyond doubt that Apple deliberately fooled the public in buying an outdated device (see excerpt of article 37 below):
And again this comes back to a retail level because as soon as the iPad 4 was release Apple stopped selling the iPad 3 on it's websites around the world.
The only way Apple could be sued is if Apple Stores continued selling the iPad 3 without making customers aware of the new model.
This sounds more like Apple being an easy target because of who they are, thats assuming the story is even true, which I may not be.