I don't keep up much with F1 at all. I thought Hamilton won every race in recent years. I guess not this year.

Wow, didn't see that coming. Hats off to him, he did what he wanted and now can focus on his family/other less stressful things.

Very interesting to see who takes his seat, Verstappen would be a good choice of course but I'd be very surprised if Red Bull weren't more competitive/closer to Mercedes next year. I would love to see Alonso in that car as I'm not convinced Mclaren can turn around their fortunes before he retires and he still seems to be driving as good as ever.

He had a lot of unfortunate mechanical issues that cost him the championship. In a critical race late in the season, he was leading by a country mile late in the race and the engine just exploded on him. That point difference alone would have been enough to secure the championship for Hamilton.

That's not expected. He's only 31, Barrichello was going til he was like 38.

Go out on a high I guess.

Wow that sucks for him (not really too bad since one should not expect to win every year).  Looks like he had some bad luck this year besides the wins. 

First I was totally WTF'd but now there's only respect, this sorta thing takes guts and strong character.

Wow, that's very surprising.

I wonder what he'll do now (will he completely retire from racing or will he go to DTM or to endurance racing?) and who will take his seat at Mercedes.

I actually think the opposite. What kind of strong character does it take to walk away from a sport where people are legitimately asking if he's the most undeserving champion ever? Vettel got in another car and proved that his wins at Red Bull were no fluke. What has Rosberg proven? That he was an average driver in a spectacular car and only won a championship because his team mate got incredibly unlucky.

Bravo Nico. I personally won't miss seeing him on the grid.

Should be a couple years of Hamilton victories again then

Good for him. Why stress yourself when you're good for life.