Preaching the Sermon on the Mount

I have been preaching through the Gospel of Matthew and have finally come to the "Sermon on the Mount" (chaps. 5-7). The sermon poses a number of hermeneutical obstacles for the expositor. How do you understand 5:17? How do you understand the nature of the kingdom as it relates to the present and future? Is the sermon for the church today? How should we understand Jesus' use of the OT and is His usage normative for today? Not to mention the difficult ethical statements that pepper the sermon throughout. I will try to give a brief overview of the various views of the Sermon on the Mount in a future post and conclude with my own thoughts. In the meantime, I would like to hear any insights some of you may have into some of these issues.