Given something like this was foreshadowed by the Curator, it's just a brief special, and DW does "let's bring back past Doctors" for specials on the regular, why does it being a regeneration make it insulting instead of fun?

Especially since we know literally nothing about the story right now. It could be a dream, or some other shenanigans, just to mess with our heads. I mean, isn't Donna at risk of death if she ever meets the Doctor again? So if she's involved, there must be shenanigans afoot, right? Not that DW doesn't play fast and loose with its own lore, but that doesn't exactly argue against my point. {= P

~Neshomeh