The banking *product* developed and installed by my company supports only IE.
There was a query from a bank's customer whether they can use FireFox instead of IE because of security reasons. I was happy that he asked but sad that the product cannot.
FireFox is definitely getting popular. But companies think that they can do without supporting other browsers. I do popularise FireFox in the bank where I do implementation. Hope i wont be kicked out for this.