According to the New York Daily News (GAYS RAGE VS. POL: State sen.'s same-sex marriage stance opposite of nabe's: group by Brendan Brosh, Tuesday, May 26th 2009), one of the opponents is State Sen. George Onorato, a Democrat representing western Queens. According to this news story, marriage equality advocates "say the lawmaker is out of touch with his district, home to one of the city's largest gay and lesbian communities." But his Chief of Staff Janet Kash is quoted as saying, "We're getting a lot of calls, e-mails and letters from both sides."
The Daily News story also says:
Senate Majority Leader Malcolm Smith (D-St. Albans) has said he won't call for a vote in the Senate until enough support is lined up to pass it. Of the seven senators from Queens, Onorato, Frank Padavan (R-Bellerose) and Shirley Huntley (D-Jamaica) have stated their opposition to the bill.
The Daily News story mentions that there will be a pro-marriage-equality rally in Astoria on Sunday. I found no further information about the rally via Google News.
Another recent news story (Support Grows For Same-Sex Marriage by Jennifer De Pinto, CBS News, May 27, 2009) discusses various poll results showing that support for same-sex marriage has grown amongst the general population.