Well, let's just say it is bad for Kamsky.

Sorry, if that is the case then I don't understand Antillian's post. Perhaps you would like to elaborate on it Antillian?

That's right, statistics and lies are closely related if you are not very very carefull.

Find all 2600+ meeting 2600+ in the French perhaps could be more fair!?

I agree with Hacker, there definitely seems to be some kind of trend. Also, before I checked the data I have had that opinion myself that above 2600 French is more problematic.

My theory is that it is relatively difficult to play white in the French. Black's plans are often a bit more easy and straightforward. But on higher levels, with the necessary skill, black gets more problems.

Would be interesting with similar data on other openings if someone has the time/inspiration. Or perhaps break it down on French sub-variations.

If any of the posters here ever has the "problem" of relying on the French and then reaching 2600 or 2700, I would argue that the time spent studying and playing French positions is still not wasted, even if you ultimately have to switch.

The typical French closed centre with its thematic fights is relevant for so many topical openings, like the Caro-Kann (Advance and Fantasy variations, among others), the Nimzo-Indian, the Torre, the Trompowsky, the Catalan, the c3 Sicilian, the Grand Prix Attack, Open Sicilians where Black gets to break with ...d5, some Modern Defence lines, the Alekhine, the Keres System against the English - the list goes on and on. I am certain that a talented 2600+ player with French experience will be able to make good use of his deep understanding of closed centres and pawn chains when rebuilding his top-level repertoire.

Here are some statistics of white's score from my DB:
Both players 1.e4          1.e4 e6
2700+          55.8%       60.6%
2600+          57.1%       60.7%
2500-2600    54.6%       54.8%
2400-2500    54.7%       55.3%
2300-2400    54.3%       54.7%

A bit curious numbers...

I suppose you can say that the French is slightly worse than other e4 defences, but I think this is mainly due to the Sicilian success.  
Also, there is some support for that the French is "good up to 2600".

Why do 2600 players score best with white?  Well, at least in general you could expect that the advantage of white increases with rating but the draw-tendency catches up.

Game Shirov-Kagramanov, Canadian Open 2009 is given here: http://www.chessgames.com/perl/chessgame?gid=1548002

Shirov played French as Black and worked about French Advance after his work on Sveshnikov's analysis and books...