This news comes courtesy of gamesindustry.biz (and forum member Nanny):
Electronic Arts has said that FIFA 10 has become the fastest-selling sports game of all time, with 1.7 million units sold in its first week.
The game is EA’s biggest European launch to date, with over 10 million online matches played and over 155,000 users online simultaneously during peak periods.
You can read the article in full over here.