I've been following the forum for a few weeks (new member here!) and started with the ERE village and tumbleweed thing and my whole thought was "EcoVillage". I know a lot of people seem to think that ERE personality doesn't work in such an environment, but I think that's actually what would make it work.
Many may be loners and the thought of doing "community" is out of the question, but I would suggest anyone even considering such an idea read one or both of the following books:
Finding Community
Creating a life together
Both are by Diana Christian, who's written for a while on EcoVillage living and put together some books for learning what to look for in joining a community or building one from ground up.
I think one of the issues is the term "ecovillage" which tends to just think of a bunch of eco warrior hippies living in huts and planning the next anti-nuclear protests. It's something that many "intentional communities" (the more correct term for what we're discussing) go through and why many fail miserably.
However, the idea of an ERE community is somewhat solid:
Smaller eco-friendly housing. It may not be just for the environmental aspect, but this type of structure is meant to maximize space, and minimize cost in both construction, maintenance, and utility usage.
Usually revolves around some sort of food sustainability. This fits ERE as many have already or plan for having gardens or keeping animals to reduce the grocery budgets. Having a larger community property generally puts you in a more rural (code friendly) area for keeping animals and generally provides more space to have these animals away from direct living quarters.
Ability to share costs/items and the economies of scale. One thing that I think immediately stands out are things like larger appliances. Does every household NEED a full laundry facility? I see some here talking about doing things old fashioned by hand, but the ability for 10+ people to share a laundry machine (as opposed to buying one or spending $ a week at a laundromat) allows you to share costs of items that each would use minimally. Same could be said of other things like tools, lawnmowers, etc, etc. Having one central area to share means nobody needs to buy and maintain individual items.
Same thing goes for land. We all love recreational land, but typically it's too expensive to buy a lot of land for one's self. However, as you buy land in larger quantities, the price per acre goes down and everyone has access to much more acreage for the investment.
I think it's good when the intentional community is around like minded people. Considering ERE -- things like water tables would (likely) not be the concern that would divide community as the like minded concerns would be around fiscal items.
While I'm not retired, and don't know that I plan to be in the very short term...it's these things that make me think I'd want to live in community. Sadly, many that I've researched are "stone age" style and go off-grid to the point where there's no access to the outside world, which I enjoy just a little too much. :)