There's a whole industry of eating locally sourced meat where I am ('The Republic of' Boulder, CO). Eating locally sourced meat is feasible here, but the product itself is expensive due to the limited supply local farmers can produce. This leads to high prices, which many people aren't willing to pay.
Interestingly, though, it does create a group of people who's lifestyles have adjusted to accommodate those costs. They aren't necessarily rich, they just choose to get around by bike or by foot, and spend their leisure time hiking and volunteering in community coops. Because of this, there are people here who sustain themselves purely on local seasonally available food.
Having lived amongst and having grown up with heath nutty hippies my entire life, my opinion on the subject is: Veganism is bad.
When I say this, I speak of people who live a *purely* vegan diet. I grew up with kids who where vegan from the beginning, and at least in younger kids, it leads to all sorts of issues, mostly stemming it seems from hormone imbalances.
Getting a well rounded diet on food products of which no part is derived from animals in extremely difficult, and requires the individuals involved in the diet to fundamentally change the way they live. It's not to say it's impossible, but veganism is a diet that requires a degree of accommodation that fundamentally makes life so difficult, you already need to have a pretty comfortable and easily adjustable life to make it work.
As an experiment, I think people could benefit from taking ideas from veganism. Expand your sources of protein, diversity your diet, maybe take ideas from the paleo system and mix that in too. Maybe even alter your diet to favor locally available seasonal products, but I recommend not going cold turkey and going all into any particular diet.
There are a lot of diet trends out there. Find what diets interest you, and shop them al a carte.
I've lived in Boulder 24 years, and I've worked in the natural and organic grocery industries for 7 years. I've seen diets come and go, and I've done the ordering and merchandising for many of them.
I feel like I know a bit about this subject, but I'm neither a nutritionist nor a doctor. This is all anecdotal from my experiences living in a very health conscious culture and working in the industry that provided food to these communities.