I for one do not trust facebook with any of my data. From a professional standpoint though, it opens up some interesting avenues for microtargeting in advertising.
It might open up some advertising channels, empower social engineering and law enforcement. I don't see how this is going to affect Google. Someone enlighten me on this
I'm very curious to know if they'll open up the API to third parties. Might be some interesting applications of this technology for virtual assistants a la Siri.