Well, here it is:
More about it (though not much more!) at
http://www.bbc.co.uk/doctorwho
My first reaction was... it's okay. I like the idea of the TARDIS shape for the abbreviated form but overall it feels a bit cartoony - the sort of logo I'd expect on a web based animated series like Scream of the Shalka. It will probably grow on me, especially after seeing it in context of the new opening credits.
I am a little disappointed that the 'O' in Doctor Who isn't Matt Smith's head. Okay, not really but it would have been very funny!
Who do you think will be the first pedant to complain about the squared off light in the TARDIS form?