I picked up Disciples 3 on the release day, the boxed version. I played for a few hours and then put it on the shelf for later. I ran into various of the already mentioned bugs and issues. It is a very pretty game and the atmosphere is well captured and fostered by the att style (it's really well done), but it does need a few patches and definitely more maps. I had waited for years for the game, so I can wait a few extra months.
I'd disagree with the statement that "Disciples 3 blows KB out of the water". We get too few games in the genre for this to be a "either/or" decision, but the two King's Bounty games are gems of the genre and except the three AoW games I have not enjoyed a fantasy TBS as much as the KB games
Vmxa makes a good point about Crossworlds and Civ5 coming out next month, and in two days there will also be Stardock's Elemental, which loks promising (the complexity and gameplay, not so much the visuals).