Nick Bostrom seems to think it's useful to alert the UN to AI. The UN is currently the best thing we have that handles international cooperation.
I'm toning back my response. Nick had said previously that he didn't think policy action could help the field of AI now (except perhaps more funding) but that it could help prevent other existential risks. There still has to be some reason why he made this talk, though.
http://webtv.un.org/watch/chemical-biological-radiological-and-nuclear-cbrn-national-action-plans-rising-to-the-challenges-of-international-security-and-the-emergence-of-artificial-intelligence/4542739995001
Exactly what it says on the tin. It starts around 1:50:00. I had trouble buffering for some reason, and I couldn't find it on YouTube.
EDIT: It's on YouTube now: https://www.youtube.com/watch?v=W9N_Fsbngh8