Originally Posted by codename_47:
“Welllll...
RTD had her dead at the end.
Moffat saved her.
Make of that what you will.”
Moffat has always said it was just an offhand comment he made, he was surprised when she did survive in the finished episode and even more so when he was credited with being the reason she did so.
I think if it had been some long term plan by Moffat to use her again he would have done it by now.
That's not to say the character won't ever come back but I think it's more likely to be under a future show runner than Moffat.