The world will never go vegetarian while there's a single living animal left on earth, not without a universally accepted and completely convincing meat substitute. That substitute will almost assuredly be in vitro meat, non genetically modified animal muscle cells cultured in bioreactors and exercised on substrates like yogurt's Franken-cousin. It may sound unappetizing, but in vitro meat has the potential to be identical to real meat in taste and texture while being far healthier than either meat or the current meat alternatives. In vitro meat will be free of fat, free of antibiotics, free of gluten, free of phyto-estrogens, and potentially free of additives and other undesirable toxins like pesticides. Whether a new stew of undesirable chemicals becomes involved in the manufacturing process remains to be seen.
Even if it's not perfect out of the gate, in vitro meat will improve as the technology matures, and market forces will ensure it leaves the starting blocks competitive with the already high bar soy, wheat gluten, and fungus based fake meats have set in health and taste.
While all this pseudo-carni-gastronomy may perpetually put off die hard foodies, they matter not at all; McDonald's ubiquity has not been obstructed by anyone's informed disapproval. If the Great Vegetarian and Vegan War of the New Millennium is to be won it will be won because we have found a substitute for the slurry used in chicken McNuggets, not because we have grown the perfect fake lamb chop that will fool a New York Times' food critic.
And while the soy, wheat gluten, and fungus based fake meats have made tremendous progress over the last twenty years, I suspect the carnivores will forever see stigma attached to them because they aren't descended from the dominion of animals, "as God intended". In vitro meat, on the other hoof, they'll likely buy as a lesser leap of faith. First they'll buy it without realizing it is ingredient number three inside their Swanson Hungry Man microwave meal, then within a few years they'll buy it from their grocery store pseudo-butcher to take to their in-laws' July 4 barbecue.
Cows, pigs, chickens, turkeys, et cetera will be safe, to become unprofitable, unpopular, unnecessary, and perhaps culled or left to their own devices in a world harsher than their domesticated genetics can survive. I hope we can gather enough of our humanity to let the last of the animals raised for meat die of natural causes in comfortable circumstances. But whatever their fate, the generational cycle of suffering will end, and that is the most important goal; and it is achievable, in our lifetime.
To that end, in 2008 PETA launched an In Vitro Meat Challenge PR stunt, with a $1 million prize for the first company by 2011 to commercially sell an in vitro meat product. While that was an unrealistic deadline given the state of the technology and the FDA approval process, it is predicted that in vitro meat will come to store shelves as early as the next 5 - 10 years. In the mean time soy, wheat gluten, and fungus based fake meat products continue to evolve, with new incarnations arriving on store shelves and in restaurants monthly.
It is a good time to be a vegetarian or vegan, and it's about to get much better, whether or not you like the pseudo meats.
An interesting video about the recent announcement by scientists at the University of Missouri that they've perfected a soy product that eerily simulates the texture of chicken.