If viewed from the top, and imagining a clock face, we zone in at 6 o'clock. Between 7 and 8 o'clock has the entrance to the Hall of Arms and Library, 12 o'clock is the Baron's northern tower, and 3 or 4 o'clock is the Alchemist and Armorsmith's eastern tower. The wall sections that span between each tower entrance are divided by these short columns.
The main features of the inner ring are two distinct things:
1) I want the raid to zone in and immediately have an overwhelming sense of the castle rising over them. They can pan their cameras up to see the towers rising in front and to the right of them, and see distinct areas that they'll be encountering later (the Baron's observatory, the Alchemy Lab) the instant they are inside the instance. I actually want them to be able to see these features from outside the instance as well, but zoning in really gives them a sense of "we're on GO. Those areas, way up there, are Park Place and Broadway. Let's get crackin', I wanna get up there and see what's in store for us".
2) The instant they zone in, they're also confronted with the Gatekeeper Boss, the initial gearcheck of the zone. There's no trash beforehand, the instance starts directly with her, similar to how Razorgore was the first thing you saw upon zoning into Blackwing Lair. The main area of the inner ring is pretty barren, except for the guardian herself, and her two crystal pylons pulsing gently. The actual section on her will breakdown that fight, this section just covers the ring itself.
Similar to the entrance area of Naxx, just zoning in should give you an immediate indication of how 'finished' this Raid ID is. With Naxx, there are the little glowing eye things that light up when a particular wing is cleared. With this area, the pylons themselves play a part in defeating the Gatekeeper, but once defeated, they also play a role in opening the final (northern) tower entrance.
The Gatekeeper herself drops a 'small key' that can be used to open either of the minor wings of the dungeon. The raid chooses which to open, but can't open BOTH. Once they've chosen, they need to clear that entire wing, whereupon another small key will drop off the final boss allowing them to open of the other minor wing.
As the final bosses in each of the minor wings are defeated, a lever is flipped that allows for the activation of the pylons in the courtyard below. These emit beams that focus on the final tower's doorway, nullifying a magical barrier that surrounds the door, and allowing it to finally be breached. Thus, zoning in and seeing the Gatekeeper tells you the instance is fresh. Zoning in and not seeing her, but not seeing any beams yet, indicate that she's dead, but neither of the sub wings have been cleared yet. One beam up = one wing down, etc.
If we wish to have even greater granularity, once we 'enter the west wing' the western pylon could glow faintly indicating that that wing has been entered (but not cleared yet). It all depends how far we want to go with this, or if people even care to see the progress of the dungeon indicated in this manner. The option is there, though.
