Yesterday, Macworld ran an article on Android's popularity among US businesses. In a survey of over 1,600 corporations, Android's growth is more than 20 times higher than that of the iPhone. In fact, 16% of respondents said their firms are already using Android devices, up from 10% just three months earlier. By contrast, iPhone use increased to 31%, up from 30% - growing, but not nearly as fast as Android.
Still, despite the fact that Android has experienced significantly more growth in the past few months, keep in mind that the iPhone already has nearly twice the market share of Android.