It's not bad, probably not as long as you might like, but you can always play through with each character to get a little more playing time from it.
There are less common drops, but nothing near as detailed as Diablo. I haven't gone back through the final quest much to see what else might drop, though. The items that you can buy will change as you acquire more gold and level up. I think that what's in the game will enable you to go back and run roughshod over most of the early quests once you've completed the later quests (at least as a Warrior).
8 Retail 1000s, 1 Retail 250, 11 Arcade 200s, 1 Arcade 250
360 in a day: 22 Jan 2008
Best achievement: Virtuoso on Rock Band (finished vocal solo tour on Expert, 50 GS)
waiting for Skyrim