I have also been looking into this stuff for a while. Apparently there are not that many tail risk funds, the prominent ones being Taleb and Spitznagel's Universa and Bhansali's LongTail Alpha. Obviously, all these guys have tons of papers and books on this topic. Spitznagel provides some nice case study on prototypical tail hedging in his book called The Dao of Capital: Austrian Investing in a Distorted World. Another interesting place is Chris Cole's Artemis Capital Management. I am not sure if his fund specializes in tail risk hedging, but his views on volatility and long term asset allocations seems very peculiar. Yet another crowd is vol guys at banks -- they may not be net long or net short vol, but high volatility is definitely better than no volatility for them.
On the other side, you have got places like AQR, MSCI, and pension funds. What is interesting about them is that they tend to be proponents of systematic factor based investing. AQR and MSCI have pointed out that (systematic) long vol loses money over time and there is no way that these funds can recover even if there will be a catastrophic event. Their research is compelling, no doubt. However, what about discretionary long vol strategies? As in, you are not ALWAYS long vol, but you construct your portfolio in such a way that it actually won't bleed during normal times. Does this bring us back to market timing issue? Do people like Taleb/Spitznagel de facto have to be right every ten or so years because of the broken clock phenomena? Or do they actually posses alpha skills?
But what happened to diversification in March? We have seen that neither bonds nor gold was good enough hedge in recent market rout. The only greenery that you could find was vol. Maybe this will make people re-consider their asset allocation?
So there are lots of questions than answers. And as always, the truth seems to be somewhere between the "long vol bleed to death" and "short vol blow up spectacularly" extremes. Maybe that's why some people end up in philosophy instead of being PM ...