Why this particular play? Well for one thing, it's the 400th Anniversary of Shakespeare's death, and many theaters are celebrating by doing his plays. For another, it's a political season, and Macbeth is about an ambitious, ruthless man who seizes political power by the worst possible means.
Sound uncomfortably familiar? We should at least be thankful we have a choice in the matter; Presidents are not Kings, not yet, anyway. In Macbeth's time the game of thrones was entirely out of the public's hands.
But for me, Macbeth is not primarily a political play. It is a psychological study of a man who is at war with himself. Macbeth embodies the ideals of the pagan hero. He is brave, ruthless and strong. But he also has a moral nature, he is aware of what is right and what is wrong. There is a christian overlay in his psyche, eroding the conviction of the pagan notions that guide him on the battlefield. Scotland is a borderland, between Christian England, and the barbaric Norse. It's a borderland fraught with peril, inside and out.