Official Review is up:
http://www.nfl.com/videos
On the celebration no-call, it's confirmed that it was missed because it was far longer after the score than is normal. Pereira says that the covering official did everything he was supposed to - in other words, the mechanics make that a penalty that's unlikely to be called as no-one's looking for it.
There was a penalty on the fumble at the end of the game, which gave the replay official time to look at various angles. He did his job; he confirmed that the call was correct (which Pereira and the referee also believe it was, having now seen the replays). In future, though, close but almost certainly correct calls which could be game-changing that late on may be referred down to the referee more readily than is current practice. The replay official phoned the tv crews, to say he'd confirmed the call, apparently, which is why the commentators were saying that it had been reviewed.
At the end of the first half, the personal foul by Arizona prior to the interception would have been tacked onto the end of the run, so if the interception hadn't been run back for a touchdown, Pittsburgh would have got an extra play. (I didn't realise this, and it seems counter-intuitive, as the foul played no part in the events following the interception. But I'm just a fan, not an official! How is it in other rule-sets?)
Finally, roughing the holder is a foul, though note that running into the holder isn't (unlike running into the kicker) so there needed to be an element of unnecessary roughness. Pereira said, "he's not coming off a block"... I suppose running unstopped in the direction and running over the holder was enough to count as 'roughing'. He said he's not seen the foul called before!