Cynically, I would say it will be lots of floor-to-celing glass, harsh acoustics in public viewing areas, and limited platforms to keep it looking 'themed' as an indonesian forest.
(The howletts tiger platforms are gloriously ugly, especially those almost-vertical 'ramps' in the paddocks where the sumatrans now are, but the tigers seem to make great use of them). I can't see London going for these or lots of mesh, remember 'the bars are coming down', right? As to whether they'll craft little water features and planted areas/barriers to reduce pacing, remains to be seen. Even with the current design making long stretches to pace unavailable, they still seem to do it even in the tightest spots.
I would be over the moon if, even for £5 million, a howletts-style paddock complex appeared on the south bank with the tigers able to look out over the canal all day on platforms.