Possible spoilers:
I'm not quite so fast. It didn't come to me until it asked if there was anything else it could do to help him and he just walked away. My brain was screaming "Make a dummy Doctor! Shrink him for a bit and let him hang out with the itty bitty people and the jellyfish looking robots!" It was just a bit to simple for me. After all the complex and crazy things that have happened this season, the ending seemed like a cop-out. But the River/Doctor scenes where great and warmed the frozen cockles of my heart.

I flove them.
I agree about the cop out ending. First of all, we clearly saw the dying Doctor start to re-generate (definitely in last night's episode, and I'm pretty sure in "The Impossible Astronaut" too) before River finished him off with a couple more blasts. Why would a dummy Doctor re-generate? It's just an animated dummy, not an actual Time Lord.
But more importantly, I thought the whole point of these fixed points in time was that they had to happen. Like, for real. The resolution to last night's episode amounted to a slightly higher-tech version of sticking a photo of The Doctor's face over a shop window dummy and blasting that to pieces, and apparently that worked?? So presumably the explosion of the Mars base (another fixed point in time) could have been avoid by simply building a paper mache model and blowing that up instead? Sorry Mr Moffat, but I don't buy it.
Ignoring the ending though, I did like the episode. I thought the concept of all points in history occurring at 5:02pm on a single day was great. I now want to go on one of those trans-globe steam trains.

The script was very well written (as usual) and was able to transition from funny to moving very adeptly. This is exactly why I was so glad Moffat took over as lead writer on the show.
I looked up the real ages of the cast. I always knew that Alex Kingston was older than all of them, but she is more than twice the age of Karen Gillan and 20 years older than Matt Smith. I saw a comment on Tumblr saying "Eww, a 20something year old making out with an old lady."

I didn't know that 48 year old women were old ladies.
I think any women over 27 are old ladies, aren't they? :

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