Wibbly Wobbly Who ...

So,
at Trenzalore, the Great Intelligence jumps into the Doctor's time-stream and starts changing things.
 

Then Clara jumps into the time-stream, and attempts to rectify things.
 

Then the Doctor jumps in, and apparently the time-stream starts collapsing in on itself.

And after all this, Clara sees a face she hasn't seen before - in any of her myriad incarnations:

It's all gone Wibbly Wobbly ...