I don't really have a dog in this fight. Weiner isn't my representative. But I think all the cries for his resignation are just grandstanding from both sides of the aisle.
As far as we know, he has broken no laws and engaged only in consensual relationships on the Internet. If his wife is willing to put up with this, we the publilc don't really have a say. He's a creep; but he's not a criminal, and the issue of whether he should stay in Congress or not is up to his constituents at the next election. The ethics committee might have a call on the "behavior" issue, but there's no crime here.
Now, what about this new x-rated photo that Andrew Breitbart is flogging around? Andrew Breitbart has a public record of using doctored media to smear his targets: the faked videos that brought down ACORN were used to launch his BigGovernment.com site; he posted the edited video that got Shirley Sherrod fired from the Dept. of Agriculture. Ms. Sherrod later sued him for defamation. If the only evidence is a photo from Breitbart, there's no evidence.