I've decided to not trust anything that anyone connected with the show has said about the 50th anniversary. Going by Moffat's track record on winding us up, I can just see him being interviewed following the airing of Day of the Doctor and saying "Of course all the classic Doctors were always going to be in it - it's the 50th anniversary, did anyone really think I was going to leave them out?!" - I seem to recall he said something similar about the twelfth Doctor being male.
We don't even have a trailer yet, aside from a few confirmed cast members and the presence of the Zygons we know next to nothing.
Excited? It's like staring at that huge present under the Christmas tree wondering what in the universe it could be.