Confirming what everyone suspected, comScore reports there are far more combined iOS users (iPhone, iPad and iPod touch) on the Internet than Android users. But remember, this survey is snapshot in time. Android caught up and surpassed iOS on phones very quickly. So far, that's not happening even remotely in tablets. But that doesn't mean it won't.
comScore’s analysis of the unduplicated audience reach of the Apple iOS platform across iPads, iPhones and iPod Touches revealed a combined iOS installed base of 37.9 million users. The installed base of iPhones slightly exceeded that of iPod Touches, both of which were approximately twice as high as the number of iPads. Interestingly, among the 37.9 million consumers with access to the Apple iOS, only 4 million (10.5 percent) accessed the platform via more than one device. The combined 37.9 million iOS users is 59 percent greater than the 23.8 million combined Android OS installed base, which includes users of both Android phones and connected media devices such as the Samsung Galaxy Tab
-comScore press release, April 19, 2011 (via Techcrunch)