Target is moving to the pin and chip system for cards (hence the new card readers). So all of the debit cards and store brand credit cards will be pin and chip only...which is more secure than the disastrous magnetic strips.
Visa is dragging their feet on this technology while MasterCard is ready to go...so in January the Visa will be dropped from those with the Visa cards and MasterCards will be issued in their place. They will still have a magnetic strip for those stores who need that technology, but will have the pin and chip which will need to be used at any retailer that uses this technology.