"Before you can gain entrance, you must first pass three tests. The former commanders of Elona await you at the base of the Rock itself. They will tell you all you need to know."
Augury rock was an important part of Guild Wars Prophecies because it was the story mission where your character reached ascension. It's clear that the Guild Wars 2 team wanted the iconic location to be an important part of the Elon Riverlands map. They pay homage to Guild Wars by including Josso Essher, a forgotten, as a world boss. In the Guild Wars 2 iteration, Josso Essher has been branded by Kralkatorrik but in Guild Wars he was originally a boss in a different mission called "Thirsty River". Josso Essher will often summon doppelgangers of the people who fight him, which is a nod to the fight your character would have against a doppelganger of themselves as the final mission to become ascended.
There are other NPCs in Augury Rock that make an appearance in both games as well. In the first game they're mostly there to just point your character in the direction of the three missions you need to clear to gain access to the interior of Augury Rock. In Guild Wars 2, Ritual Priest Zahmut has taken to standing outside of the closed mesa and telling travelers of the forgotten unless Josso Essher has been defeated. He then moves to an interior chamber and stands with Joziah, Mendoza, and Valodor.
A lot of the desert in this Guild Wars 2 expansion has replicated Guild Wars locations perfectly. I've honestly been a little spoiled for choice in what to take pictures of. It's really easy to match the maps up thanks to several standing markers, labeled points of interests, and surprisingly a lot of the same landscape shapes.
The best way to get a look between both of the games is to stand on the very center of the 'transportation pad' just outside of the mesa (for Guild Wars it's the one nearest to the glowing rocks and in Guild Wars 2, it's where Dawnwynn stands). If you're looking to view the inside of the mesa between the two games, in Guild Wars 2 it's best to ride the event train until they defeat Josso Essher. In Guild Wars you'll need to have cleared the story up until that point and then I suggest taking ranger as primary or secondary profession and only having your pet equipped (Comfort Animal) instead of any other skills. The pet will likely keep your double busy while you spend time exploring, just make sure to keep them healed.