Over at Slate, Dahlia Lithwick breezily but effectively dismisses the lame slippery slope argument against gay marriage.
Richard Goldstein parodies conservative fears of petaphilia over at Village Voice.
The argument that gay marriage will lead to incest, bestiality and polygamy is pretty easily dismissed really: there are arguments against all of those things which simply don't apply to gay marriage--or homosexuality itself for that matter.
The more the dialogue continues, the only argument any on the right are going to have left against homosexuality is that the Bible says it's wrong. Then they'll have to deal with the fact that the Bible puts being gay on equal footing with being rebellious or eating shrimp.
Once they agree that the only argument they have left is on biblical grounds, they'll have to realize that they have to convince the rest of us that the Bible is the inspired word of God before we'll let a two-to-six thousand year old book start bossing us around.