After all those years of blitz training who would've thought that Naka loses the blitz playoffs!
One more reason to play blitz chess

you know they invented these things called videogames, right?
If I want fast-paced fun without thinking too much I'm gonna play Quake and throw rockets up somebody's butt.

Actually from the first post you could conclude that playing blitz does no good as Nakamura plays a lot more blitz than Kramnik. [you do not have enough date to make much of a conclusion]
However if you like to play blitz there is nothing wrong with that as long as you do not have the delusion it will help your slower game very much.

Ponz, no. It means that Kramnik also plays blitz, and plays it well!
We are seeing some fantastic blitz games in the play-offs of the World Cup.
Blitz chess alone will not raise your game to master level. Even Nakamura didn't just play blitz, he studied and played at standard time controls too. But of the the three types of chess, blitz, standard and correspondence chess, the one that is not necessary for improvement is correspondence chess. Correspondence chess players must excel in research, note taking, and other habits that have little to do with chess strength. I do love correspondence chess, but it's not a necessary component of chess development.

SmyslovFan, I concede your point about blitz.
However there is more to today's correspondence chess than research, note taking etc. The best Correspondence players [today's best players] also have to
understand well all the other parts of chess such as positional play, endgame play, pawn islands, strong points, bad bishop, good knight and especially they have to know how to change[for the better] existing opening theory.
[I know many disagree with me on this]

I play much stronger blitz chess than slow chess. I think it's because my intuition is good, but my calculation is not always so good, and so something I calculate out (wrongly) in a long, slow, OTB game and therefore not play is perhaps the winning move and something I would play in blitz. I need to work on this, I know. Haha
Vladimir Kramnik just beat Hikaru Nakamura in a blitz play-off in order to advance to the finals of the Geneva Masters Tournament.
The link below shows the match. The commentary is in French.
http://www.chessbase.com/Home/TabId/211/PostId/4010326/geneva-masters-sf-kramnik-and-mamedyarov-win-300613.aspx
Blitz matches have become one of the most common forms of tie-breaks in standard chess tournaments, and not just elite events. Many events that have a single champion are now decided by rapid-play, blitz and armaggedon play-offs.
I have never seen an OTB tournament decided by a correspondence game.
So, blitz chess is not just addictive fun, useful in developing intuition, practicing openings, and recognising tactics, it is also useful in determining champions!