I don't mind DLC at all as long as it adds a decent enough amount of content to the game to justify it's price. Take the new ArmA2 DLC for example - an entirely new playable faction, new vehicles, weapons etc, for a reasonable price. And the clincher? All the engine updates that are released with the DLC will be made available to everyone via a patch, regardless of whether they purchase. That's how to do DLC :)