It's on some former antelope paddocks and the woods behind (the former inhabitants of the paddocks all seem to be on the large mixed African paddock with the giraffes).
Looks like it's coming along well - hoping to be there again in 2012 and looking forward to seeing this. The current elephant/hippo house is one of the very few remaining outdated exhibits in the zoo.
The old pachyderm house should be trasformed into "Amazonia". The reptile curator has a free hand to come up with proposals/plans for future exhibits. It is still open what will live there, probably a mix of smaller animals with emphasis on cold-blooded ones.
But with funds becoming scarcier every day, it is all still just a big wish. I see the possibility that the recontruction will not come immediatelly after the elephant move and the old house will be temporary filled with some undemanding mammal species (capybara&Co.).