I've been watching this, too. Gotta agree with most people's comments, especially about the 'evicted' pairs.
Hens would have been my first choice, so long as they were layers. Immediate income potential from genuine free-range cluckers, especially if they were a pretty breed that would add marketing value to the eggs. We have just six hens at the moment and they lay far more than we can consume so we sell the surplus to friends and neighbours. I'm looking at doubling the flock size shortly.
Pigs would (and did, I think) go through some of that fencing like it wasn't really there. I'm not a fan of electric fencing, especially for intelligent determined animals like pigs. Ours would make minced meat out of it. I wouldn't have thought any more than 2 or 3 on half an acre though, but at least they can plot-share with the hens.
Goats - I seriously like the idea of being able to sell goats milk and cheese but haven't looked into the legislation - no doubt it's pretty strict. I'm told they're also pretty good escape artists, which would be a problem for our neighbours.