I unfortunately didn't see the race and, because it's always popping around on different channels here, it didn't get recorded, so I'm not able to watch that either. But, reading the comments on it, and the discussion of the incident and driver comments, here's my take on what happened...

Some drivers, through a history of aggressive, no-holds-barred driving develop a psychological advantage over their rivals in critical situations. Schumacher was one of those drivers, who you knew would absolutely not give way at a critical moment, the most extreme example of which is perhaps the 2005 U.S. Grand Prix when he forced Rubens Barrichello down the run-off following his pit lane exit to prevent Barrichello taking the lead in this otherwise bizarre race. Barrichello knew that Schumacher would not give way at the last minute, and, in fact, Schumacher held his line until Barrichello was forced off the track. In this game of chicken, Barrichello "knew" that Schumacher would wreck them both before he would give Barrichello room to go around him on the outside, and Schumacher used that "knowledge", or, more precisely, fear, to his advantage to keep the lead in an otherwise (almost literally) uncontested race.

Hamilton is also one of those drivers who plays this game of chicken to his advantage and has a history of forcing other drivers off track by an absolute refusal to ever yield an inch and aggressively using that reputation to his advantage at every instance. In fact, this was exactly what was going on in Hamilton's head at Hockenheim when Hamilton crashed into Button: Hamilton just assumed that Button would let him past because he expects everyone will let him past to avoid a collision.

So, should Rosberg simply give way and signal to Hamilton, "Do what you want to me on the track because in a tight situation, you know I'll back down first?" Or, should he, championship lead in hand, deliberately, "make a point," and let Hamilton know that he cannot assume that Rosberg will back down in a critical situation, even at the risk of taking both cars out of the race. This is the point that Rosberg wanted to make to Hamilton, and I suspect that Hamilton may be a little less sure of Rosberg yielding to him in the future.

So, was it deliberate? Yes. Did Rosberg cleverly puncture Hamilton's tire while limiting his own damage to a tiny bit of front wing? No. He knew he was risking taking himself out of the race. He also knew that there was no certainty that he would come off better, or even not worse, than Hamilton. But, he did it anyway, because he wanted Hamilton to know that he cannot expect a certain win in a  game of chicken with him. Rosberg knew the stakes, knew that he might end up taking only himself out of the race, but he did it anyway to send Hamilton a message; and the next time they find themselves in a similar situation, Hamilton will be that much less certain that, in a game of chicken with Rosberg, he will escaped unscathed. This is a high stakes game where you cannot gift your opponent a psychological edge and expect to win.