And more importantly, the distribution in subsequent rounds. Especially the Polish and Russians are beast, but China is up there too.

(Ex-)communist countries are on top. I don't mean to imply anything with that, because I have no clue, just sayin'.

Interestingly India has so many people in qualifiers but none in the finals, now I don't know what that says about India!

Seems to me like it correlates with economy more than anything else. The best American (and to a lesser extent western european) programmers are making six figure salaries working on world class products and/or getting funding for their own startups. The best Russian and Chinese programmers are doing ... Google Code Jam.

Because the ability to code algorithms quickly is the same as the ability to break into systems.

The same type of mind is likely to be good at both, yes. [I would expect]