We've prepared a draft of a white paper describing the overall NFC ecosystem and what choices we have for NFC in Neo900:

http://neo900.org/stuff/papers/nfc-draft.pdf

This still needs some vetting and a few technical verifications, but it should give an idea of the general lay of the land and the direction we're taking. Once we've decided on a specific implementation, the no longer pertinent bits should be (re)moved and more details regarding that implementation added.

This specific version is at
http://neo900.org/stuff/papers/nfc-draft-20150105.pdf

The source can be found at
http://neo900.org/git/?p=misc;a=tree;f=nfc

- Werner