The original source is the NPD report, but the Ars article has some interesting analysis and quotes:

http://arstechnica.com/gaming/news/2009/03/npd-group-online-gaming-rising-wii-beats-out-ps3.ars

That's pretty impressive.  Publishers and developers definitely do need to start taking the Wii more seriously, especially for online usage.  20,000 gamers were polled.  About 25% (~5,000) of them played online.  Here are the percentages of those who gamed online with each of the following platforms:

PC: 87% (about 4,350 of the 5,000)

360: 50% (about 2,500 of the 5,000)

Wii: 29% (about 1,450 of the 5,000)

PS3: 20% (about 1,000 of the 5,000)

nice wii gamers gotta represent

Just as a clarfication. I am assuming that the actual numbers are

PC 87%
360 6.5%
Wii 3.something%
PS3 3.something%

As in, the 360 has 50% of the 'console market share' for online

Anyway, huge jump for the Wii 18-29 in a year. Partially due to Mario Kart, but what other games do we think are responsible. CoD?

Can we safely attribute the bulk of that to Mario Kart Wii? I mean, Brawl's online can't account for that (though i always find a match when i feel like pissing away 20 minutes to get connected to one), and the only other possibilities would be World at War and Guitar Hero

w00t PC GAMING FTW!

didnt sony just claim that it had 20mil people that play online lol?

well we knew that was wrong anyway. but thats seriously great, i didnt know that. if only we had better online...

to find a match on brawl join allisbrawl.com

its a nice site where people post their fcs and they have chat rooms set up

theres usually good people on there, skill and connection wise

i can get a game there in like 4 or 5 minutes, and then its always a balst

Your "clarification" is really wrong.

There were 20,000 people polled.  Approximately 5,000 (25%) of them played games online.  Of those ~5,000 people, 87% gamed online using the PC.  50% of those 5,000 gamed online using the 360.  29% of those gamed online using the Wii, and 20% of those 5,000 people used the PS3 online.

For example, if I were polled I would have answered PC, Xbox 360, Wii.  Many people use multiple systems.  The fewest people used the PS3 and nearly 50% of the online gamers used the 360.

@ Phoenix - If I had about VGC$ 0.2 for each time I had exlained this, then I would, uh, have as many VGC$ as I currently do.

The 20 million figure is accounts on the Playstation Network, this means that if a PS3 user has multiple accounts they are counted twice, if a PSP user has an account it is counted, and if someone has signed up for the Playstation forums it also counts.

So no, Sony never claimed what you said they did

lol and i remember when nintendo said gamers werent really wanting to play online.

pft..