Can you imagine if in the 50th Anniversary episode, he was the War Doctor? Hurt was fantastic but if Christopher Eccleston was that character and Rose was still the Weapon... oh that could have been something really cool.
IMO Rose was always the Weapon. She just creates Rose to see if the Doctor is the right person to activate it.
Yeah, Eccleston didn't like the BBC leadership that was running the show. But since he has had a change of heart, maybe he can get in on one of the specials and we can have a 5 Doctors tale again or something