It's a rare treat to see a mock this good, so I think it's only fair that I try to give some feedback other than "excellent".
One aspect of this mock that I particularly like is the distinct colour separation between the bulletins, especially the purple for News at Ten implemented in such a way as to not ape Newsnight.
The ethereal effect achieved when the blocks almost dissolve into the background gives the titles an air of quality and authoritativeness that's unmistakeable. Applied properly, I think revisiting the map idea should make these even better - with the way you've designed it, I can see a map composed of points of light coming from the blocks as working. To be honest, it's that good that just having the News at Ten blocks emblazoned with the Many Faces of Tom Bradby wouldn't do it too much harm.
I also like the fact that whilst you've taken design cues from past brands, it is also an evolution of the current design - 2D and 3D blocks aren't that far apart. The unfussy, modern aspect of the current design is nicely carried over too, without being overly simplistic.
The theme music doesn't seem to mesh as well as it does with the current titles (not that the timing is wrong - it's bang on); I think that's simply a matter of the current titles' sharper movements fitting in with the style of the music. For that reason, the News at Ten theme variation seems to be a more natural fit, as the current 3D titles are less jaunty in their movement.
The attention to detail is excellent too - the little throwback with the italicised "at" in the News at Ten logo alone is a great touch.
I don't agree with some of the feedback here - I don't think it's worse than what we have now; given your rationale for the design and what you plan to add, I also don't agree that it lacks substance.
Ultimately, the simple fact I want to watch the video you've posted again and again is a sign that it's a mock that would be more than suited to being on TV, in my opinion.