The rumor comes from TechCrunch's Jason Kincaid, who cites "multiple sources" as quoting the high price. Two of Kincaid's anonymous sources also say the buyer is Electronic Arts. If these rumors are true, Kincaid points out that this would be a "huge bet" for EA, as $1 billion is over 13 percent of EA's market cap.
Kincaid suggests EA is trying to get out of the "hardcore" gaming market and appeal to casual and/or mobile users. PopCap could definitely help with such a goal, as it's the home of such mobile hits as Plants vs. Zombies, Peggle, and Bejeweled. PopCap also produces a number of PC games with free trials, including Insaniquarium, Zuma, and Bookworm Adventures.
For an indie games company, PopCap isn't doing too badly, with the company bringing in between $100 and $150 million per year, according to TechCrunch.
If the rumors are true, this wouldn't be the first time EA has made a large mobile purchase: In 2009, the company acquired mobile games publisher Playfish for $400 million after payouts. Then in late 2010, EA snapped up Chillingo for $20 million. Chillingo is the mobile games publisher known for the most popular iPhone game to date: Angry Birds.