My theroy
I know this is speculation. But instead of being an "8.5" or the "Real 9th Doctor", I reckon John Hurt will be playing an older Eighth Doctor. In the flashbacks, there was no Eighth Doctor, in the time stream sequence at the end when they were running past, there was no Eighth Doctor.
This way, none of the regenerations get messed around and from a story perspective it can still make perfect sense, not to mention, the costuming is a mix between 8 and 9. So that's my theory, John Hurt is playing an older 8th Doctor.
That is actually make pretty much sense... But Paul McGann and John Hurt are not similar in any way. Besides, we can actually see Eight running in the intro part (before the opening music), running just after the second Doctor. We can't see his face, but this is definitly the eight's Doctor's suit. Puchplimmirdeyslithin ☎ 23:38, May 18, 2013 (UTC)