According to this article in Vanity Fair chronicling Microsoft's "Lost Decade":
...today the iPhone brings in more revenue than the entirety of Microsoft.
One Apple product, something that didn’t exist five years ago, has higher sales than everything Microsoft has to offer. More than Windows, Office, Xbox, Bing, Windows Phone, and every other product that Microsoft has created since 1975. In the quarter ended March 31, 2012, iPhone had sales of $22.7 billion; Microsoft Corporation, $17.4 billion.