Whatever happened to Donna Noble?
We can derive from the last few minutes of Turn Left that Donna's fate has been manipulated by Bad Wolf to help the Doctor. We can easily see that. But it struck me that we can extend that idea.
What if Donna doesn't exist?
What I mean is, what if she was created by the Bad Wolf expressly for this purpose? It would cover the fact that she's apparently an anomaly and also Rose's insistence that Donna is still going to die: perhaps fading out of existence once her part is played.
The Doctors comment about (false) realities forming around her suggests that it's just what's happened and she's a 'fiction' Bad Wolf has inserted into the world. Hell, even her surname reeks of foreshadowing.
So why did Bad Wolf create her? More than just to help him out emotionally and pull himself together? Well, what about if her whole existence is a contingency for if or when the Daleks return? If they do, the different threads of fate conspire to get her to the Doctor and put him on track.
It's interesting to look at River's reaction to Donna now. Can we get anything more from that, you think? Imagine having to deal with something that thought it was real chatting about it's dreams and hopes for the future. And let's not forget she's constantly being referred to as a "temp"/"supertemp". A comment on what she really is?
More than that, I just don't know at the minute. I worry about a scene where Donna returns home and her family don't know who she is. I don't want to see the panic. I just want the character to be happy, meet someone and go live a great life.
I hope I'm wrong about this. I was bang on with series 2, but waay out there with the 3rd year finale (mainly because that was absolute mince). Poor Donna.