This New York Times article
looks into how free checking may change when new federal rules on overdraft take effect. Here's an interesting excerpt about how banks will make up for the loss of overdraft fees:
But the most popular option seems to be to get retailers to pay for a big part of free checking, not bank customers.
This is from to the interchange fees
that retailers pay when you use a debit card. The article looks into how rewards checking accounts are helping banks get more interchange fees. It also reviews PerkStreet Financial's free checking which offers a 1% cash back on debit card purchases (see my Perkstreet review