We didn't give up on it! I did, however, leave Matasano to start a new company, and that's slowed us down. We will certainly still be posting solutions.

Another problem is that every time we've talked about posting solutions, people have asked us to hold off.

Finally, a quick jab: thousands and thousands of people completed several sets of these challenges --- more than a thousand got through the CBC padding oracle, which (in our challenge) is cryptographically more complicated than the TLS POODLE attack. None of them had solutions. You don't need them either. :)