On The Jesus Blog Anthony Le Donne asked whether or not we should assess Rudolf Bultmann's legacy as generally positive or generally negative. Now, I am no expert on this matter, but I think the answer must be positive for the following reasons:
(1) Bultmann was a first class scholar, even if you disagree with him, and he will cause you to think afresh about exegesis and theology when you read him.
(2) Bultmann was not an angry skeptic trying to destroy orthodoxy as many conservatives seem to suppose. He was a modern man trying to understand how to retain what was central to the Gospel in his day and age. One may not want to concede as much ground as he did to modernism, but that doesn't mean we should see his task as necessarily antithetical to what even conservative theologians do now (save the most Fundamentalist types).
(3) Whether or not we like it, we are all playing the same game as Bultmann. If you disagree read his 1941 essay "New Testament and Mythology: The Problem of Demythologizing the New Testament Proclamation" and then honestly ask yourself whether you totally disavow his hermeneutic or if you may have adopted a modified form. Personally, I may not follow him on the resurrection, or even on spirits like angels and demons, but I do tend to seek the core theological truths in Genesis 1-11 without relying too much upon the "science" of these texts (or, the lack thereof). So at some point I tend to seek the "kernel", if you will.
(4) Even if you find most of Bultmann's conclusions to be bankrupt you will likely also find that the person whose response to Bultmann you most admire is exactly that: a response to Bultmann. As I said in point (1), Bultmann forces us to think and he did the same for his contemporaries and near contemporaries. Even when one disagrees with Bultmann that act of disagreeing makes for constructive theologizing.