There are a lot of different investment philosophies out there all competing for the attention of a limited amount of capital. The interesting thing in my mind is that there are so many different managers, strategies, fee structures and just as many investors out there ready to listen to them, including me. These days, with bonds yielding nothing and equities still very volatile, investors (especially retirees) don't know what to do with their money.
Mebane Faber of Cambria Investment Management (Full Disclosure: Cambria is a client of the PR firm I work for) has devised very interesting ways to diversify by investing in several different asset classes including real estate, commodities and foreign stocks, which are trading at historic low valuations. Overlay a risk management process that tries to avoid massive drawdowns by going into cash when asset prices are going down. Cambria just published its latest outlook on the market and compared returns over the last 40 years in various different portfolios. Like anything else, it relies on investors who don't do stupid things, like pull their money out of strategy just because it doesn't beat the overall market. Cambria's strategy didn't do well compared to the U.S. equity markets in 2011 and 2012, but over the long term it has been better with much less volatility. It all depends on how long you stick with the strategy.