I currently have two working theories on where John Hurt's Doctor fits in the timeline. All this is outside the possibility that this is really Doctor #9.
The first idea is newest so not very formed, but fed some by some of the new pictures as well as an interview with Steven Moffat in SFX magazine. First here is what he said about the matter...
"There's a whole lot of stuff you missed! It's a nice thing to be able to say in the show, and for no one to be able to contradict you, that there were years that you didn't know about... we lied and lied, there's a whole big old chapter you didn't know."
So I got the idea that this was 10.5, or The Meta-crisis Doctor who stayed with Rose in the other universe. He could be aged, his Rose could be dead. They could be taking into account the deleted scene where The Doctor gave him and Rose a chunk of the TARDIS to grow their own. Like I said, I don't have much of it worked out. But now look at these pictures:
In every picture John is BETWEEN the other two. Now I used to have theories as to why the TARDIS had so much detruction when David Tennant regenerated, like him holding in the energy to say goodbye and just put it off created the explosion. But what if something else happened. That could still be The Doctor who ended the time war.
In both cases it would be a Doctor born out of anger. The most likely in my mind is still the most obvious one I mentioned at first, but some type of shocker would really be welcome.