I don't care if it's Phoenix Saga or no Phoenix Saga, Angel or no Angel...they need to bring that cast back by any means necessary. Singer leaving sucks ass, but they could certainly do worse with the replacement. Xavier being played by someone else besides Stewart after the first two films...ugh.
And please let this be the last one. If they keep doing them, one is going to suck eventually.
I like that he saved some mysteries for later. ("Silence will fall", why the TARDIS exploded, etc.) I also thought it was funny that Amy still wants to jump The Doctor's bones even after marrying Rory.