New NPD study shows that online gaming on consoles and handhelds in the US grew from 19% in 2008 to 25% in 2009, while PC remains largely majoritary, at 87% versus 90% last year (this last figure via ArsTechnica).

That would give a graph like that if we understand it right :

Amongst consoles, 50% of console online gamers played on Xbox360, while Wii was growing from 18% to 29%, and PS3 came third.