I haven't heard what the plans are. They may just leave it for a while to let the plants get established, and then stick a roof over it later. Or maybe just to decorate the exhibit and pretty it up so they don't look empty until they know what they have some plans. Don't think it's for cassowary extension, as they are likely to damage or dig up the plants if they are scratching around in the mulch. The area currently being built for the cassowaries includes the very old penguin pool which was replaced in the early 80's, filled in and planted out. Now, more than 25 years later it's finally being used for an exhibit.
I won't be back in until February - not with these current crowds! - and I'll see if I can find out then.
yeh i checked out the foundations for the cassowary exhibit when i was down last month, just intrigued by whats goin on there in the end pool. ill try and find out before then