User blog comment:MasterCharmander13/Davros back in S8?/@comment-28119130-20140705064029

That's what I thought when I saw this first too, but as Ping said, the Prime Minister could also be it.

And another thought; we saw the Doctor's hearts, probably because the voice said that he good look in the Doctor's soul. But might this be a reference to the thing were Moffat asked fans why the Doctor could not be a Human?

I know it sounds silly, but its Doctor Who, we can expect everything. Especially with an awesome headwriter as Moffat :D