The whole exhibit was extensively redone in 2004/2005, but I don't think the size was changed. The view you are looking at in this photo did not exist before this renovation.
One of the best I've seen. There is an African style interpretive hut with skulls and artifacts and (I think) additional viewing windows that really adds to the experience.
Well, that is even more reason for me to make a return visit this coming summer. I am toying with the idea of putting together a docent trip in June to see the new Giants of the Savanna as well as Fort Worth's MOLA.
On zoolex it says the enclosures are around 1000 and 1300 square meters, which is around 10000 and 13000 square feet, very large for a gorilla enclosure but not quite as big as Congo.