As of this posting, the changes are still pretty minor but help lay the groundwork for future development in the area. The path to Marco's Dispensary now continues on, past a new man-made Mountain Spring and path through the mountain, to connect the Zombie XP Grinder and Wither Shelter to the main road network. More expansion is planned as well, but they depend on the layout of new builds in the near future.
What is the Zombie XP Grinder? For quite awhile now, a Zombie Spawner just below the surface in the Noctis Grand Desert has been functioning as a [quite primitive] Zombie XP Grinder. A lot was learned from the Skeleton Grinder, so changes are due to the Zombie one as well. As it stands right now, Zombies come up to you automatically at a killing booth at full health for you to kill, take XP from (stand as close as you can to them to get the majority of the experience) and the drops fall down into a hopper chain that takes the loot to the collection area around back of the killing booth. ("Loot" is a strong word. Let's say a bunch of rotten flesh and the occasional carrot, potato, or iron ingot)
What is the Wither Shelter? Well to tell the truth, the Wither Shelter is a bit of an exploit. Because the "mobgriefing" gamerule is set to false to prevent Creepers from blowing up blocks and Endermen from relocatng them, the Wither boss cannot destroy blocks either. The Wither Shelter, then, is a room to trap a Wither in so you can quickly kill it at minimal risk to yourself and others... in a re-purposed Desert Temple.
Members of the Superstes Noctis server are encouraged to build in the Noctis Grand Desert -- especially community builds! Be aware that there are a lot of the new "Husk" mobs out there since it is a desert biome, and they give you the hunger debuff the majority of times they touch you. Watch out for them or you may have some extra trouble surviving the night.