Saying that this television special was highly anticipated is totally underselling it. People were losing their marbles over it. Fifty years for a television show to exist is really impressive and illustrates how popular the show has been for several generations. Filled with twists, time leaps and turns it is best to go into the special with very little knowledge about the plot. Just sit back and enjoy. What is important is watching the short prequel, Night of the Doctor, so you are not completely lost.
With this in mind I will not tell you anything about the special other than it is television at its best. Filled with ingenuity and intrigue it will have you guessing and usually wrong. It is an incredible mixture of complex ideas that are presented to us in a very simple manner. Easy to follow yet there is still plenty to sink your teeth into. Enough so that it warrants multiple watches.
If the eighth season is anywhere near the quality of this then fans have plenty to look forward to.
-Behind the Scenes
-Doctor Who Explained