Aiming to be a competitor of Google, so far they are doing a fairly good job. I mean let's face it, they'll never be as big as the company but they are fast and show very relevant results.
I really enjoy the fact that they don't lock you into the bubble, which means that you get results based on your search, not based on what you've liked, searched for prior or what THEY (Google, Bing, Yahoo) think you want. They also don't store your results or search history so everything presented is not biased in any way.
My FAVORITE part of DuckDuckGo is that they have all these neat short cuts to navigate around and an awesome set of goodies that geeks can use to get better search results.
All in all, they are a huge win and I hope to see them grow.
I'll admit, I still use Google cause sometimes I WANT biased results, but DuckDuckGo is becoming something I'm using more and more.