I just returned a couple days ago from San Antonio (and other parts of south Texas). Spent one afternoon at the start of the trip and one full day at the end of the trip at the San Antonio Zoo. How long does this zoo have left? A long, long time. The new additions are quite good, especially the hippo pool which has a fun feeding/training session daily at 3pm. Some of the really bad cages from my first trip are now gone. The old rift valley exhibit is still a lot of fun, even if it is a bit of a quirky design. The elephant exhibit is not great, but not terrible either. It is better than the current one at my zoo (although we are building a new one).
The jaguar exhibit is temporarily closed and I have a feeling will be filled with another more appropriate species. The jaguar currently resides in the former leopard exhibit, which before that was a snow leopard exhibit when I last visited. It has been improved since that visit. The cranes of the world exhibit, viewed by a boardwalk, is totally unique and the nearby boardwalk over the large tomistoma pond is fantastic. Only zoo I have seen with giant anteater inside a (south american) free flight aviary.
The former caracal exhibit, which was a bit small for a mid sized cat, is now filled with much more appropriately sized black footed cats. Aquarium building is small, but they get credit for being one of the few traditional zoos with an aquarium. Reptile house is quite respectable. Lion and tiger exhibits are somewhat bland, but at least they are decent sized.
A couple sections near the children's zoo were under construction, so perhaps some new small additions coming. I will say the zoo was fairly busy both days and everyone seemed to be having a good time. I did not hear many complaints from other guests and I do not have many complaints myself. As I said in my earlier post, it will never be a world class zoo, but it is also not a terrible zoo.