Old news I know, but I was just reading about the sale of del.icio.us to Yahoo and came across this quote from Joshua Schachter:
Interestingly, Google was both least aggressive and least attractive to Schachter. When he'd interviewed for a job there, the company had told him, "We don't need idea guys--we've got plenty of them. We just need developers." Now Google was wracked by internal debate over the value of Del.icio.us. Schachter says, "They came in and said, 'Well, maybe we're kinda sorta interested,' but there was no 'What's the plan? What are you thinking about? Where do you want to take this?'"
This strikes me as a massive insight into the possible failings of Google. I'm not preaching GoogleDeath or anything, but experience has taught me that "idea guys" are notoriously bad at actually implementing things well, it's just not where their interests lie.
And any organisation which grows as fast and long as Google has to run in to serious problems at some point ... new people just don't scale very well.