Don't know why everyone is saying brilliant, great, ideal, perfect- can't think of anything worse myself and I say that as a single parent who also feels lonely at times.
It seems to me to have the disadvantages of a second marriage (day to day irritations, trying to blend families, different parenting styles) with no sex.
I don't think it's wrong to try- people move in with highly unsuitable men all the time and try to make it work (most second/third marriages fail) and your 'partner' seems like a great person but...if I had an amazing friendship, went on holidays, could do big events together (like Christmas) I'd keep that valuable thing and not try to change it into a living arrangement.
It is not similar to most of the communities/communes that I know of- in those people have their own living quarters usually and then shared space/shared food, so the community aspect is not shoved in their faces. Decisions are made democratically by the community. Even then it is stressful for some.
Living with one good female friend once the kids have flown the nest is not really the same at all. Most marriages would probably be ok if you didn't have the exhaustion of kids/parenting/stress/pulling apart- and many of the rocky one's I've known have gone on to improve once the child-rearing is over (or they just split up).
To me, two families with a mum heading each is too intense, or it would be for me anyway, but I do like to do things my own way as do most people these days. As a shorter term thing, it could be ok for a few year, but by teenage years I wouldn't think the teens would be into it much at all. As someone else said, if you think children like living with other non-related children, visit the step-parent board. It's bad enough with their own siblings...
I don't think it's wrong to try though, and no worse than what a lot of people do when they try again- it's just it'll be like a second marriage without the sex. Being with a woman isn't going to make everything easier IMO because the issue isn't whether you two get on, it's how do you combine two households, lifestyles, life needs, changes in circumstance and so on
I know many people who have lived in communities/communes and think people are idealising these situations as they are sick of heteronormative marriage, more than because actually, they'd really like to live with lots of other people day in day out!