From the Hong Kong launch it can do apps/market links to apps, as well as maps/directions (I think that was part of the beam demo, may not of been but I think I remember it during that demo), and there seems to be disagreement about whether photos can be (it seems like not directly/natively but some third party apps open that functionality)...
I have yet to play with this though...
EDIT:
for clarification, photos are too large of files to be sent over NFC, but there is work to use the NFC to open a bluetooth or wifi direct connection between the devices, and share that way. see here:
[Q] Can you send photos with Android Beam? - xda-developers