Shakespeare: Who wrote what?

Every few years this sort of story comes along. I'm not sure what to make of it, really. I love a good conspiracy theory, and I can see that there are some reasons for thinking that the authorship of Shakespeare's plays was down to someone else, or several other people. I'm not sure, though, that the reasons offered here are that convincing.
Derek Jacobi's comment that he doesn't think anyone could do it all on his own seems a bit odd - surely you could, and would, say the same about any genius, in any field? That's what sets them apart, isn't it?
His later comment, where he names De Vere the likely author because his life and experiences more closely match the plays, worries me even more. After all, no one's experience can match the plays that closely - they're just too varied and multi-layered for that. It seems to me to downplay the importance of imagination, and there's a hint of snobbery too. It must have been an aristocrat, because no pleb could possibly have managed it. Hmmm. I'm not persuaded.