Okay let me just say that I am 97% sure that this is not the last we will see of River. Obviously we have to find out how she and Clara are linked, as well as how she found out the Doctor’s name and got his screwdriver. There’s just so much more to the story that obviously the writers wouldn’t leave gaping wide holes like that in the story. This exact moment was when I knew we would see River more, so please don’t just go assuming she’s gone. I’m sure she’ll be back because obviously, there is more to learn about her timeline.