^I'm not out to dispute your point about blu-ray here, but I would like to point out that all 3 series of Sherlock have been released on blu-ray. Well, at least in the UK they have can't be certain about the US.
The Beeb is an honourable exception, but it'll be interesting to see if that continues when the long awaited BBC Online Store finally launches.
Also an honourably lousy exception at times, the Hollow Crown only got a Blu release years after everyone relented and bought the DVD.
With the upcoming full scale war between the Beeb and the Tories likely to lead to a massive reduction in the size and scope of the BBC, I'd be surprised if they punt on anything.