Bono commented about how "Acrobat" was his favorite song from AB, but to date it is still the only song off the album that hasn't been performed live to an audience.
About midway through the ZooTV tour, U2 played with the idea of doing the version of Acrobat you heard, and then transitioning into Zoo Station. They never went with that idea though, as it was rehearsed several times, but never performed. What you're hearing is a rehearsal - I have the same thing.
In my opinion, it was a good idea, but I prefer that Zoo Station be the opening song for ZooTV. It just fits better. A big bang right from the start.
Maybe someday we'll get to hear Acrobat live, but who knows......