A major trend in zoos over recent years has been the transition towards mixed-species exhibits. It's lead to a lot of experimentation as different combinations have been tried over the years - some with positive results and some... less so.
As a general rules, primates have been some of the harder animals to incorporate into mixed exhibits. They are intelligent, dexterious, and curious, often in the manner resembling a destructive, malicious child. (Of course, I've never been too huge of a fan of monkeys to begin with...)
There have been plenty of successes with even them, however, and this new display at Dublin Zoo looks like it's going to be a big hit with the visitors and (most important) the animals living there.