I went and saw it today (jbnbsn99, I heard you doing your tour, but I didn't have time to take it, sorry).
It was REALLY nice exhibit. Giant size, enough room for anything. Since I don't work for the Dallas Zoo, I'll say what I have heard while there.
-Yes, Mountain Zebra are coming although they are not yet on exhibit and won't be when it opens.
-50/50 chance impala make the exhibit by opening next week, not guaranteed.
-Ostrich, Elephant, and Giraffe are currently separated, including 2 of the elephants separated from the rest. Jenny (the original Dallas Zoo elephant) doesn't seem to play nice with others, even though she is currently with Gina. The plan is mixing all the elephants, then mixing the giraffes, then mixing the zebra, et. all.
-Cheetah and Lion exhibits could be bigger or more impressive in some ways.
Ummm . . . GO SEE IT! It's great.