As long as they keep releasing some of the DLC for free, I have no problem paying $5 or $10 for a nice, healthy sized DLC every now and again, I'd love to see them continue to add new quests like Troll Trouble, quests that are in-depth and rewarding and require you to make moral decisions, just look to the books for inspiration, there are TONS of potential DLC in them, look at Nivellen the Man in a Monsters Skin, I mean, you even have a name for the quest; 'A Grain of Truth.' That alone would make a PERFECT DLC Quest that could easily supply Geralt with tough, moral decisions to make as well as providing new gear and adding to the lore. Throw it into Act 2 and viola!
The Edge of the World Chapters from The Last Wish provide the developers with another potential DLC Quest, Geralt and Dandelion go the Valley of Flowers, throw in a few side-quests with the main-quests being to deal with Torque and then later the Elves. Again, it supplies ample oppurtunity to add in moral decisions, rewarding side-quests (Witcher's Board Quests, Arm-Wrestling, Dice, etc.) as well as new items. Of course, both The Edge of the World and A Grain of Truth stories would have be reworked to fit the timeline of the Witcher games, but the stories are there, they just need to take advantage of them. They already took advantage of the Troll mentioned in the books (Geralt talks to Dandelion about how the world is changing, as he runs into people who more and more don't want their monsters killed, specifically a troll who fixes the bridge of a local town for them, as it is easier to pay his toll than pay to fix the bridge themselves) It's all there for CDProjekt to amaze us with, and I believe they will, and I have no problem paying for it as long as they continue to make them as well-done as Troll Trouble was (the other quests for the Harpy Feathers was really more of an easter-egg than real DLC)