Reading about the cut content certainly does make you feel better about Gillian's existence. Considering as the game stands, she's a completely useless NPC. Not only does she not offer any services, but she doesn't know anything about anything. She's always like, "Hmm, don't know much about that. You should ask this person or that person...."
p.s. Yes, anakyn. Didn't take note of their name though. Shall I manually change it for them the next time I see them
Yeah, there was tons of content that was originally meant to make it into Diablo but never did.
As with many games, Diablo was originally intended to be much more expansive than the final product, with a large number of monsters, characters, items, and quests never making it into the retail release. A large portion of this content is still contained on dormant files hidden on the CD of the game.
Some spells never made it into the final game. The original game was supposed to have six spell-book pages (this can be checked in Diablo's manual, page eighteen, in a screen-shot where the spell-book has six pages), unlike the four in the final, and the spells left on the CD are: Invisibility (whose icon graphic was reused for the Teleport spell in Diablo II), Blood Boil, Blood Ritual, Doom Serpents, Etherealize, Sentinel. Most of these spells are disabled, but some, like Etherealize, can be enabled with the help of hacks, and Doom Serpents' graphics can still be extracted from the game's main data file.
Some enemies don't appear in the final game, such as the Unraveler (which is now a monster found in Act 2 of Diablo II), Goat Lord, Incinerator, Bone Demon, Invisible Lord, The Arch Lich Malignus, and Devil Kin Brute. Their images can still be viewed in sprite form (.cl2) in the game's main data file. Several of these monsters later appeared in the expansion, Hellfire.
A character named Tremain the Priest does not appear in the final game, but there are sound files of his speech in the game's main data file. He was supposed to travel in and out of Tristram and was to trigger of the "Fleshdoom, Wielder of Shadowfang" quest, which also never made it into the game's final stage. As originally planned, Tremain was to give the player a quest to destroy the demon Fleshdoom and retrieve his cursed sword, Shadowfang. However, when the player returned the demonblade to Tremain, he was to be consumed by hellfire and slain. He was also said to have been supposed to guide the player through the "Archbishop Lazarus" quest, instead of Cain; the reward in that quest was to be a powerful unique mace called Lightforge. Since the quest was not removed, it is not possible to obtain a Lightforge legitimately; many players have used third-party programs to gain this item, and some have even changed it into other forms to create Lightforge helmets and armor.
Many hints for quests that never made it into the final game can still be viewed on the game's main data file. These include "Izual, the Fallen Angel", in which the player talks to Gillian the barmaid and receives a quest to find and destroy Izual to release his tormented soul. The reward of this quest was likely Azurewrath, a unique sword. Both the quest and the sword were used separately in Diablo II. Another quest involved hunting down the demon queen Andariel. This character appeared later as a boss in Diablo II.
Two cutscene's appear on the CD but not in the game. One of them is a video the player is supposed to see upon entering The Butcher's lair, and the other one is of Diablo gaining power if the player fails the (never implemented) Map of Stars quest.
Many item graphics were never used in the final game, including the Map of the Stars, which was hacked many times into the game and spread over Battle.net. When the stars become aligned, Diablo will become "all but invincible", so the player had to complete this quest on time or else one "may never have a chance to rid the world of his evil ever again." This is the only quest of the whole lot which was ever officially recognized by Blizzard. They said that it was turned off because it "changed the way you played Diablo."
One of the extra sub-quests from Diablo supposedly involved Gillian. Gillian was involved in two quests, the first one she would issue early in the game. Rumor has it that Gillian requested that a cellar is cleaned in one of the town houses as "Giant Worms" had invaded the cellar. To complete this quest, the player needed to enter a town house. There is an abandoned house inside Tristram with an opened door which could possibly be the house the player was meant to clean up.
It's believed that Blizzard originally only planned to have one character skin. This is backed up by early screenshots, which not only showed only the warrior skin, but also depicted the warrior skin using magic and ranged weapons. The early names for the classes were the Fighter, Archer and Mage.
Oh man! Bloody brilliant! See folks, this is why the first Diablo kicked so much ass. And has anyone noticed how the Death Knights and Protoss Zealots die the exact same? They even make the same noise.