Pope Benedict's first encyclical doesn't rank up there for most Lutherans with, say, the shorts recently released by Old Lutheran.
Nevertheless, I do believe all of us can benefit from reading encyclicals promulgated by the Roman primate. Deus Caritas Est, published on December 25th, 2005, has not (as Richard John Neuhaus notes in the May issue of First Things) received as much attention as some of the encyclicals of Pope John Paul II. This is unfortunate. If you've never visited the Vatican web site, let the encyclical be your first stop.
If you're familiar with the theological writings of then Cardinal Ratzinger, you'll find many themes recurring here in this encyclical. If you're influenced by Augustinian and Lutheran theology (as are most Lutherans) then you will find some happy congruities between your tradition and the Pope's, who has been a consistent friendly reader of Lutheran theology.