The 'Happy Families' exhibit area seems obsolete now they have effectively replicated these exhibits in the children's zoo. As popular as short-clawed otters are in their current exhibit, I think they are one of the few animals that could be well-suited to the lubetkin penguin pool, if furnished, with a 'retired' pair or single-sex group, putting them in the water-themed area of the children's zoo. The meerkats get much more attention in Animal Adventure now and there seems little point holding a second group by the Clore.
As for the ring-tailed lemurs, the problem with housing this species in an old concrete monster like the roundhouse (though masterfully redecorated and furnished) is that you can see this species in more attractive surroundings in almost any other UK collection, so it leaves the zoo looking like they can't somehow house their most identifiable lemurs in large open enclosures.
I hope ZSL has plans for this whole area, and that the Happy Families enclosures were just an experiment leading up to the opening of Animal Adventure. Meerkats and otters are certainly modern day, crowd-pleasing species for the general public.
I like the idea of bringing the primates in the lion terraces over to this part of the zoo. If Drusillas were able to create an open-air enclosure for its Sulawesi macaques on a relatively small patch of land, as they did so this year, perhaps it would be possible to do the same at London?
I would love to see the roundhouse used to house the gibbons, with an overhead rope bridge into the trees on the South bank. I'd actually REALLY love to see overhead primate bridges connecting open-air compounds on the north and south banks crossing high above the canal. If Dudley can get the funds together to fence off a bit of dense vegetation, I am sure London can too.
As for the lemurs, I've often thought 'Meet the Monkeys' would work better as a lemur exhibit, given that the Clore lookout is kind of a walk-through monkey enclosure, and possibly a better place to exhibit the ring-tailed lemurs than outside the Roundhouse?