It seems that, historically, the source of misdirection most used by magicians was spiritualism. Naturally, an increasingly faithless and sceptical public was no longer impressed by this sometime around the early part of the last century.
I think what happened subsequently was that, while magic went mainstream, it became a cliche. Shorn of misdirection, magic is simply quite naff, because, ultimately, we know it is a trick.
I think Derren Brown has shown the way forward in terms of bringing psychology in as the major component of misdirection. But this is now itself become almost as antiquated as spirituality as we learn the limitations of psychology and it becomes obvious how prosaic many mentalist tricks actually are.
Do forum members have any suggestions as to where to go from here? Some ideas to get the ball rolling:
1) Science? People's faith in science is extraordinary, comparable to that of a primitive people's belief in all-powerful gods. People know enough about science to know that amazing breakthroughs are being made, but not enough to know exactly how.
Problems here-lack of visual interest, difficulty of presentation in general.
2) Lucid Dreaming - most people have experienced lucid dreaming and know it is a very powerful thing, but again don't really know how or why it works.
Problems here-a very narrow field. You could ascribe all kinds of powerful behaviours to lucid dreaming techniques, but very difficult or impossible to present in a stage context.
3) Gambling-skills used by professional advantage gamblers in casinos can be extrapolated. To some extent this territory has already been covered by mentalists, though there is a lot of potential here.