Errrr. these research companies generally over estimate things. They said that netbooks would sell in 2013. By January 1, 2013, no netbooks were in production.
Although 1 billion sounds a bit high, I guess 750,000 would be more likely. Those with Win 8.x and Win 7 would upgrade in the first year for free. Others would come by dumping [finally] their XP and Vista systems]. Minimal amount from Surface and Win Phones. Big business would start in the second or this year.