Full marks to Bleeding Cool for their article How Doctor Who’s 50th Anniversary Looked When Christopher Eccleston Was Still In It – And Billie Piper Wasn’t. Drawn from the recent release by storyboard creator Andrew Wildman of sketches from Day of the Doctor it gives a fascinating glimpse of the anniversary show we could have had.
No sign of the Eighth Doctor but it does show how the War Doctor was injected after it became clear there would be no Ninth Doctor. Plenty of basics are there for the Tenth and Eleventh Doctors.