Yeah and they're not linked together. I don't know how viable it would have been but I'd have scaled them back to 45 minutes and tried to squeeze a third one in the middle, there's really no reason why either ep is an hour long, both are v padded. I'd have had Cristina go with the Doctor at the end of PotD, but then I'd have had something bad happen to her in the new middle episode, which then leads into WoM and gives added impetus to the whole Timelord Victorious malarky.
I also would have had Christina go with the Doctor at the end of "Planet of the Dead," and then when they visit Bowie Base One she gets infected by the water. This would make the Doctor feel especially helpless (he can't save Christina, he can't save the base), and that's what kicks him over into Time Lord Victorious mode.
The BBC does this not infrequently, but it's usually with more mainstream fare, such as crime dramas. IIRC, this was the first time they did it with a sci-fi series, certainly the first that I remember. And yes, the premise of COE was helped greatly by this airing.
Yeah, thats a good idea. Although annother good idea would be to have her depart at the end of time after the doctor regenerates ad she's scared off or something. Or I'd have just given him a new permanent companion which would have gone onto the post Tennant era. Maybe have Amy Pond introduced after the xmas special.