The Nexus One leaks are deliberate. No, Google may not have actually sent the photos to blogs themselves, but giving the device to that many people just before the holidays? It was basically guaranteed. They knew it would happen.

As far as Google's leak control, I think that they can be secretive when they want to be. Part of that comes from the fact that they have so much going on — you hear a rumor and it could well be related to some random research project or internal test, etc. But I've been to a few Google events where there were product launches that hadn't been previously rumored.

A good example is probably the Chrome launch. As far as I can remember, there wasn't any significant buildup in rumors of a "Google Browser" in the weeks before that announcement. Granted, the cat came out of the bag when a mailing company accidentally shipped the Chrome comics a day early, but that didn't come from an employee leak.