Well, I downloaded the Titan Quest demo last night, had insomnia so played from 2:30 until 4:00. Definately looks like it's potentially the successor to Diablo 2 : gorgeous graphics, very clean interface, and a lot of ways in which it has improved upon D2. Including having 8 different player class / masteries, which over the course of time you combine any _two_ of. Want to be a warrior or a hunter, but also want an earth elemental to guard your back? It looks like it's possible
And the map system, the quest interface, having multiple skill points to spend each level, three filters for looking at loot on the ground (all items, unbroken only, and non-normal)....
Definately the game I'll be getting next when it's released, supposedly in June.