Really really nice and very different from other audio mocks. Nicely done.
Two things I'd change:
I'd firstly add a bigger BBC News growl at the beginning (I'm sure you know what I mean).
Secondly, I wouldn't add the vamp like you've done 8 seconds or so in. The dum-dum dum-dum is slightly out of tune and I think it sounds just great the way it starts.
I would like to try out your mock but I cant seem to download it and is very interested after reading the comments given by friends here at tvforum so can you upload the file again?