Target says that it has no evidence that debit card pins were compromised.
Update: Dec. 21
The Washington Post reports that its former security columnist Brian Krebs actually broke the Target story on his security blog, and his latest report is here. Target is offering discounts and some free credit monitoring and still denies that debit card pins were compromised.
Debit cards can often be used as credit cards without pins, and the charges are easier to reverse when fraudiulent. This happened to me once in March 2013.
Update: Dec. 28
Target is admitting that debit card pins were taken, but not the encryption keys with them, that are outside the company. However consumers with easily guessed pins (like "1234") could certainly be at risk.