Ah, but that's not the high-definition package! That will attract a premium.
From more reading it looks like that was just a guess at a price (no-one has been given any official pricing information), but even if they only stick a £10 premium on that's over £50 a month.
I've got the £20 package (everything except movies and sports... think it might have gone up actually), and watch it for about 2 hours a week in the end... If I went for the full package then my Sky box would be earning the minimum wage!