Blacks voted overwhelmingly for Obama both times. In return they have suffered more during this economy than whites. Most blacks are socially conservative and are horrified at the gay marriage business. Recall that black churches were instrumental in defeating the ballot measure in CA.
So having been screwed financially, having been promised a bunch of stuff that still hasnt been delivered on, having their values crapped all over, will blacks get the idea that Democrats are the party to exploit them and at least stay home on election day?
As a black person and an active member of a black Christian church your OP is pretty much targeted dead center at me.
With that said, I can tell you this, although we're not too enthused with the whole gay marriage thing, we aren't appalled by it either, and we certainly AREN'T even THINKING about running to the GOP. That party simply doesn't speak to us, not in its current form at least. In fact, we mostly feel that its actively against us with their seemingly racist rhetoric and voter suppression tactics. You people have A LOT of work to do, if you're hoping to have blacks come to your party in any significant numbers.