Will credit cards become obsolete? I don’t think so. I still write checks for some things, but it’s becoming increasingly rare because one can use a debit card for most purchases these days. In one respect, NFC will be just another mechanism for people to make purchases, but it’s worth watching if you are a contingency planner or auditor. NFC promises to be convenient, and the wireless phone companies will see a lucrative new profit stream by cutting out the credit card companies and becoming the middle man themselves.
I keep one folded-up check in my wallet for the rare occasions I am in a place that does not take a credit or debit card. Perhaps people will keep one credit or debit card in their wallet after this technology comes along, in case their cell phone battery dies, they are out of wi-fi or 4G range, or they drop and break their phone. After all, contingency planning scales down to the most basic level, does it not? Good luck in your planning.