But there's more on show than the new character class, says Wilson. "One of the huge new things for Diablo III is the skill-rune system. Runes can be found throughout the world as loot. You can apply them to a skill in your skill tree, and they dramatically change what that skill does. As an example, the With Doctor class has a Plague Of Toads skill, where he throws out a bunch of toads which hop out and explode on your enemy. Now, you can put a rune on that skill which turns your toads into flaming toads. Flaming, exploding toads. You can then put another rune into it which turns it into a rain of frogs from the sky, so it becomes an area-of-effect skill. And there's a further rune upgrade where, instead of lots of different toads, it becomes one giant toad that sticks its tongue out and grabs guys, and spits out the loot".
That's potty, and pretty far-reaching. There are five different kinds of runes, and seven different strengths for each rune-type. Given that every skill in your skilltree can be upgraded in this way, there's massive scope for modification of your character's abilities, and the ability to personalise your character way beyond the cosmetic. That's going to be a lot of fun when you take your character online.
And that's the other big development since Diablo II. Multiplayer, which will be tied into Battle.net, is way more accomplished this time around. It takes two forms - co-op and PVP - and while the Diablo universe is distinct in its own right, it's plain to see that the Diablo team has learnt a lot from World of Warcraft. There's a definite air of similarity, as you combine skills to tackle dungeons together.
Co-op is a blast. With two buddies at your side, the action ramps up enormously, and the dungeon in the demo build became an indoor fireworks venue as three of us lit the walls with our combined spells and effects. We found ourselves tearing through the environment, melee up front and ranged behind, and making light work of the smaller enemies. But over-pacing yourself comes at a price. At one point, the Monk melee-specialist I tried out found himself a little too far ahead of the group, and suddenly, fatally, beset on all sides as he reached a crossroads.
PVP takes place in arenas, and is uncompromisingly swift. Playing with fellow show-goers, our mixed group (Warrior, Wizard and Demon Hunter) found itself hopelessly outclassed by a party of three Wizards, who'd been playing together in co-op previously. They hit us hard at range before we could close the gap, and we fell repeatedly to their summoning spells and ranged-damage bolts. I felt an enormous desire to really tinker with my character, to tweak its skills and gear for PVP.
Don't hold your breath. With much of Blizzard geared up for the launch of World of Warcraft: Cataclysm in early December, the focus isn't on getting Diablo III out of the door anytime soon. But if there's one thing that our time with the game has hinted at, it's that Diablo III will be worth the wait.