Primarily, NFC is much lower power consumption than bluetooth, much smaller field, and much lower data/bandwidth. NFC is more in the category of RFID.

Secondly, NFC tags are unpowered and rely on the reader for energy. They store several dozen bytes up to several thousand bytes and are useful for QR-style applications, like "Tap here for our address" and so forth. I did up some business cards with tappable tags on the back that take a device to my website. They also make tags fully embedded in paper and cardboard for cosmetic appeal.

NFC tags are very cheap, on the order of a few cents each up to a dollar each, and are therefore well suited to the smart objects applications such as, for example, tapping a pill bottle to retrieve non-trivial amounts of information about the medicine, or storing identity information on personal possessions.

Really, the applications are endless. I think Apple has missed the ball on this one. They should have included NFC early on. You can buy an iPhone case with NFC, which is useful but of course it's never as good as having it built in.

(Interestingly, the linked article is on TechCrunch, a news website that recently published an article "NFC = No One Fking Cares!". Of course, the author, a journalist apparently with no engineering background, drew a lot of caustic comments for that one, and subsequently I stopped reading that publication. This iPhone 5 article is poorly edited; it's too bad this out of probably dozens of choices is the one that made it into YC.)

In my mind, NFC has always sort of felt like a clunky way of imposing a physical constraint on what should be a purely electronic transaction.