Google analytics tracks visitors from mobiles that supports full browsers (supports HTML & analytics tools). Google analytics reports visitors from iPhone, the T-Mobile G1, and other mobile devices with full (HTML) Internet browsers. To know whether a particular mobile supports full browsers check the manufacturers website for information.
To eye on the iphone visitor report in Google analytics select "Visits from iPhones" in the Advance segments drop down. By default Google has created the segment for easy glance at the report. I am glad that Google is getting geared to enter the mobile web analytics market to compete with the top mobile analytics vendors such as Bango, Mobilytics etc.
Comon Google! You can capture the mobile analytics market......