Doctor Who 50th Anniversary Ident and Hashtag Revealed Tonight

There's now only 8 weeks until the Doctor Who 50th anniversary hits our screens and the BBC is beginning it's celebrations tonight with the reveal of a new ident and #hashtag that will be used throughout.

The official Doctor Who site says:
Tonight, immediately before and after the brilliant Atlantis (BBC One, 8.25pm) there will be ‘stings’ for The Day of the Doctor that reveal the ident which will be used for the episode, plus a hashtag that (hopefully!) you’ll soon be very familiar with…
And what of the eagerly anticipated trailer? .. well fear not as it is on it's way, the BBC say:
Stand by for several surprises en route to the 50th… One of them is a brand new trailer, specially written and shot for The Day of the Doctor. It’s never been seen before and is currently in post-production. Bold, brilliant and unexpected, it promises to be an ideal way to look forward to the big day – 23 November.
Videos will be available on the official Doctor Who site afterwards.