I think it's Doc 8.5; post-McGann / pre-Eccelston. I would then assume that he was the one who wiped out the Daleks and the Time Lords.
I remember in Parting of the Ways, 9 had the chance to do something similar (albeit on a smaller scale) and couldn't so it makes sense that someone other than the 'Doctor' could.
Personally, I think McGann into Hurt may be a forced regeneration at the hands of the Time Lords. Not only would this kinda make sense that they'd try to make a 'warrior' (they also brought back The Master to fight in the war - they were that desperate) but it would also give the 'Doctor' even more reason to be pissed off at the Time Lords.