Nate Silver runs them:
A statistical analysis I conducted last month, which was based on the results from previous gay marriage referenda in other states, gave the Yes on 1 side just an 11 percent chance of prevailing, although the fraction rises to 32 percent after an ad-hoc adjustment for the fact that this is an off-year election. In spite of the PPP poll, I'm not especially persuaded to deviate substantially from those numbers: the polling average still favors the 'No' side, albeit narrowly; the 'No' side seems to have run the superior campaign, and the cellphone issue may be worth a point or two. The tight polling, certainly, should keep everybody on their toes, and gay marriage could quite easily be overturned. But I'd still put the Yes on 1 side as about a 5-to-2 underdog.
A victory for equality would be a huge boost to efforts in New York, New Jersey and Washington DC to get equal treatment under the law.