Sorting out a bit of the above answer of JustinAngel:
RFID is not a predecessor technology of NFC
RFID covers various frequency bands of Radio Frequency Communication (e.g. HF and UHF)
NFC is Near Field Communication and usually covers HF (13.56 MHz)
Many standards fall under HF NFC: ISO14443-4, ISO15693, FeliCa, ISO18092, .....
NFC Forum is trying to unify things and uses NDEF messages to exchange semantic messages
contactless payment on credit cards is based on a contactless smartcard layer.
WP8 allows only exchange of NDEF messages
WP8 does not allow exchange on the contactless smartcard layer (ISODEP==L4==(T=CL))
see the windows proximity api for details or http://developer.nokia.com/Community/Wiki/Use_NFC_tags_with_Windows_Phone_8
Android however gives access to this ISODEP layer
I don't know what credit card information could be retrieved from an app. There is a secure element involved which handles cryptography and stuff. I don't think detailed information on Mastercard payPass or VISA payWave is freely available