I agree with Nea; the alliance just un-happened itself.

I expounded upon that last night, as only a comic book nerd can do. :)

Even RTD never did a cliffhanger this intense. Amy is dead. The TARDIS is destroyed. The Doctor is imprisoned (and possibly never ever existed, depending on how certain dialogue is interpreted). The universe itself goes silent.

To quote Murray Gold, "Moffat, what have you done?"