I think the universe has two purposes: to irritate me, personally; and to make it blindingly obvious to anyone whenever I, personally, am an idiot. Note that the second purpose complements the first.
So Obama picked Biden, and I don't like the choice. He failed the same radio test that Obama passed spectacularly: I turned on the radio one time to hear someone give a speech without knowing who. In Biden's case I kept asking myself why this guy is so annoying.
My opinion didn't change during the primaries although I'll admit that he did well in the last debate I watched, and also I can't say I really know that much about him. I was disappointed to see Biden was a big supporter of Kosovo independence and supported the Iraq war resolution (although he and Richard Lugar did try to replace it with something more moderate until they were sandbagged by Dick Gephardt). Anyway, I don't see a Chris Dodd figure taking unorthodox stances that turned out to be right. Maybe I'm wrong.
So if Biden's a bad choice then it fits the universe's first purpose, and if he's a good choice then it fits the second purpose. We'll find out which.
UPDATE: After having just read the relevant section of this, possibly the last (only?) intelligent thing written by Glenn Reynolds, I'd say Biden's 1988 plagiarism scandal was overblown.