Sahil Kapur’s rundown of the current situation in the fiscal cliff impasse/embarrassment is a very useful guide to the politics of the situation. The short version is (still) that Obama has all the leverage. (There are millions of cynical Democrats, of course, who are waiting for him to squander it.)
Also worth a look is this quick NPR piece looking at the prism of the cliff negotiations through the prism of, well, negotiation theory (though I wish the piece did more to tie the experts’ stories into the actual matter at hand).