At the New Orleans Comic-Con, Matt Smith had this to say about the potential of future River Song episodes:
I'm really possessive over Alex [Kingston]. I said this to Steven [Moffat]. I was like, 'Listen, just don't! Just not Alex. Anyone else, but don't give [Capaldi] River.' But Peter is the Doctor now so hey, what can I do?"
It's still unclear whether or not the Doctor's wife will return in Series 8. Is she all but a memory like on Trenzalore, or are there more spoilers we should look out for? We'll all just have to wait and see.