Bank of America announced they have 10 million mobile banking users, 3 million of which joined over the last 12 months.
Bank of America has been pretty aggressive in mobile banking supporting all modalities (SMS, mobile web, smartphones), all major smartphone platforms (iOS, Android, Windows Phone, BlackBerry) as well as tablets (iOS, Android, and Kindle Fire).
My Take: Since mobile has become such an important of the way people connect to the Internet, mobile banking has become an expected feature of any bank just as online banking is. The fact that BofA customers are conducting over $1B in tranactions weekly through mobile shows customers are actively managing their accounts via mobile (e.g. transferring fund, paying bills) and not just checking balances.