Despite the name, I would be very surprised if this level started its life as Waldo World. Not a bad arena, actually. Now works on all maps.
Based on a net map Bungie was demoing at MacWorld, but with M1 textures (natch). A fast-paced, nicely laid-out map.
A central pillar and four outside rooms. All the good ammo's on the pillar, but you're such an easy target...