The New Family Tax Credit is just as it is written: a credit for families. There are a few limitations on it, including a cap in the dollar amount. It works best when the couple make different amounts. It also requires that the couple have a child under 18 years of age. It gets a little more complicated in some situations, so contact your tax professional for more information.
Update: This credit was removed by the new government, so is only good for some previous years.