The Meat Debate
Even with all those reasons against meat consumption, the truth is that there are nutrients necessary to proper human growth, especially of the brain, such as vitamin B12, biotin etc., which you can mostly get from animal products, or some herbs and sea vegetables that are not as easily available or that don't provide as much of the nutrients required.
Because I've been a long-time student of this debate, (I still eat grass fed humanely raised meat that has not been treated once a week), I was excited when I learned about Dr. Weston Price's research of nutrition in Nourishing Traditions, which according to Sally Fallon and Mary G. Enig (food activists and nutrition experts) "demonstrated that humans achieve perfect physical form and perfect health generation after generation only when they consume nutrient-dense whole foods and the vital fat-soluble activators found exclusively in animal fats.” The urgency of Fallon and Enig's work is of "restoring nutrient-dense foods to the American diet through education, research and activism."
Although I know I may never have all the pieces to the "perfect nutrition" puzzle, I don't believe in one sided research. And living in the Bay Area, one can easily become "one more vegetarian," vegan, or be into paleo, or follow an all organic or macrobiotic diet, because we have great quality grocers, farmer's markets, and restaurants that cater to those nutritional lifestyles. But I think a little responsible meat eating once a week (until I find the best alternative) or when I eat out is okay.
If you are puzzled by the labeling of meats these days (I think we all are), here's a little cheat sheet from Issue six of Meatpaper. 
This means meat that is minimally processed with no artificial or synthetic products. It is not regulated, however, so anyone can put it on their package. This claim has no clout.
COOL (Country of Origin Labeling)
USDA regulated. It states where meat was raised, slaughtered, and processed (and if this means multiple countries, as in the case of some ground meat, they should all be listed).
USDA regulated. It means, very narrowly, that animals eat grass. According to the USDA definition, “grass-fed” animals can also be fed grain, and can be raised on grass in confinement, as long as they have access to pasture.
[The Omnivore's Dilemma documents that "access" can be -- and often is -- nothing more than a facility with a door to a small outdoor area. Livestock is transferred to this facility after they have been conditioned to remain indoors in a facility with no such exit.]
This means strictly that the animal has some access to outdoors. There is no regulation for use of this term, except in the case of chickens raised for consumption. “Pasture-raised” is a more meaningful term concerning the animal’s welfare.
USDA and third-party certified. This certification means that livestock wasn’t treated with hormones or antibiotics and was fed a pesticide-free diet.
Refers only to an animal’s diet and does not guarantee the animal was pastured or raised humanely.
This article addresses the treatment of living animals. Producers and retailers may also make claims about how the animal is handled between slaughter and purchase. Meat may be wet or dry-aged, frozen, and packaged in various ways.
HUMANELY RAISED; CERTIFIED HUMANE
Many ranches now choose to undergo an audit by third parties such as Animal Welfare Association and Humane Farmed to high-light their extra care. This type of label wards against practices like overcrowding, castrating, early weaning, and denying animals access to pasture. It measures the entire life cycle in terms of animal health and well-being.
This pre-organic standard treats the whole ranching operation as an interrelated whole. While some meats are technically organic, a biodynamic farm assures the meat also came from a healthy, self-sustaining system.
Producers who take part in this affidavit program state in writing that the animals were raised within 20 miles. This label is not certified [or confirmed] by a third party, such as the USDA or a labeling certifier. 
It also wouldn't hurt to get to know your local butcher. Here in Berkeley we are lucky to have The Local Butcher Shop on 1600 Shattuck Avenue (entrance on Cedar), a sustainable butcher shop owned by a Chez Panisse Alum. It's fun to know your local food experts. I've gotten tips on how to cook things I've never eaten before from farmers at the farmer's market, and that gets me really psyched to bring new things home to cook. So get to know your local butcher or rancher if you want to get to know your meat.
1. The Case Against Meat
2. It’s a Jungle Out There: What do meat labels mean? by Marissa Guggiana on Meatpaper: Your Journal of Meat Culture. Issue Six