I'm probably going to get this set, as the Battle of Geonosis and Arena Battle scenes were some of my favorites from the entire saga.
I do hope that the three Arena beasts are included (Nexu, Reek, and Acklay), but this already seems very likely. I wouldn't mind seeing the Reek and Nexu being new with no electronics and articulation in the legs, but I'm not going to hold my breath. In addition to the beasts, I'd be happy with Padme, Obi-Wan, and Anakin with three pillars or 3-5 Sun Facs repainted as Geonosian Warriors. One last item the would be cool to see is the sonic cannon that was supposed to come with the Arena Playset back in 2002.
Overall, I'm kind of hopeful about this set and I am also very curious as to how it will look in its package.