I was expecting 3 million for Twilight so too high, but like has been said its demographic is more likely to see it in the cinema or watch it on DVD, or on Sky, than to wait for it to be on TV, its only going to pick up people thinking "this Twilight thing is everywhere, might as well give a shot"
I dont think the OKTV! ratings mean much, Big Brother has not launched yet, so people wouldnt think to watch for that reason, that reminds me, is it BB host Brian who does the voice over on OK! magazine ads? If so that is pretty impressive brand syngery from Desmond.