If someone wanted to move US$100K anonymously using DRK, their buy (and subsequent sell which everyone would cry "dumper...!" at) would shift the price substantially. So it's currently just not usable for its intended function and we need to get it to be.
What if someone (or a group of people) with a lot of DRK would sell them, and agree to buy them back with exactly the same price (and perhaps take a small vig) for a duration of a week or so?
What would we need to be able to pull this off trustlessly and in a manner where a lot of people could offer their coins for sale, and the system would hold the fiat (or BTC) for the duration, and the buyer could "redeem" the fiat (or BTC) back within a time frame? Maybe the fiat would make this impossible, drk/btc could be doable.
Person A will buy DRK for $10,000 from the system, and will get a token/guid/hash/proof/passphrase called X. Next, person A will anonymize the coins and send them and the proof X to person B (B could be A, or a merchant, or anyone really). Finally, person B will send the coins and the proof X to the system, and will get back the $10,000 - vig. What sucks about this though, is the X, which will link A to B. And probably something else sucks as well, just something I though about when thinking about the slippage problem.