Until recently, I never gave much thought to the Shakespeare Authorship question (and it looks like I'm not alone from this survey by the New York Times). [UPDATE: Looks like the NYT has put it behind their registration wall. In any case, not many college professors spend much time on "the question."]
On a lark, I picked up the Audio Book Shakespeare by Another Name by Mark Anderson, an account of the life of Edward De Vere, the Duke of Oxford in which De Vere is put forth as the true author of Shakespeare's plays. I can't say that I'm 100% convinced, but his argument was fairly persuasive. At some times, however, it really seemed like he was grasping at straws (the hidden coded images in the first folio's pictures sound like they came from the Da Vinci Code, not real life), and the connection between William Shakespeare the Actor and De Vere seems a little weak.
What's interesting is I also recently read Greenblatt's highly-readable biography of William Shakespeare as the author of the plays, and there are a number of points that seemed a bit odd and forced in that story too, although using Shakespeare's text, Greenblatt draws an interesting characterization of the Bard of Avon's life and mind.
I didn't realize the amount of rancor behind the battle between the Oxfordians, Stratfordians, et al., but it seems to come down to a deeper question than a simple historical question. In some ways, it comes down to a discussion of the nature of the genius behind these works and the nature vs. nurture argument.
Can the genius of Shakespeare come from the mind of a simple glove maker's son, or does it need to develop from a rigorous education? Each theory holds a certain appeal to me. The poor boy makes good through his own powers is the classic American story in some ways, but it smacks of a certain predestination in which Shakespeare is almost super human. This is the Shakespeare that barely ever needed to blot his paper because what was written once was perfect. On the other hand we have De Vere's approach in which a man struggles, writing multiple drafts of his plays over many years, basing them on an education steeped in a wide variety of subject areas. Suddenly, Shakespeare's less of a god and more of a man, and he's certainly much more approachable. This theory leaves me with a bit of hope that anyone can, through hard work, achieve brilliance.
In either case, it's the works of Shakespeare that are important now, rather than the life of he who created it. Still, it's fun to have multiple lenses from which to view the plays.