As far as I can tell there is no aftermarket at all for them. In the past year I think I have heard of only one low three digit sale, so the odds of ever making a profit on them would seem to be close to zero. I have bought a grand total of one (an excellent keyword) and after trying to sell it for a year (for as low as $10) with no success, I let it drop and won't be buying anymore
Well I recently purchased a .cc domain which I paid a low three digit figure. I will develop the name into a full fledge site as an addition to our network. Unfortunately from selling/reselling point of view, .cc names are still very weak. I must say though I like the shortness and easy feel of the extension and hope that it will get more popular as the time goes by.