"The final scene of David Bradley and Matt Smith in An Adventure on Space and Time is rather like the Tenth and the Eleventh respecting and legitimising the actions of the War Doctor, acknowledging the debt they owe to him in The Day of the Doctor. John Hurt is or becomes the Doctor because they take responsibility for him. The Day of the Doctor's wonderful cameo featuring Tom Baker as 'the curator' also operates in a similar way. The past and the future overlap. One cannot exist without the other. Tom, as elder statesman, is saying to Matt, and similarly the Fourth Doctor is asking the Eleventh Doctor, not to forget those whom have served, whether in the Time War or in Lime Grove D. These scenes don't just serve as a kiss to the past, they - to put it in Moffat-ian terms - positively snog its face off and use tongues."In case you're wondering I still haven't watched it again. It's almost like I'm running away from it.
TV Because I didn't, if you want a proper review of The Day of the Doctor which covers all the bases and even has some screenshots, let me direct you towards Frank Collins's on his Cathode Ray Tube blog: