Brad Wardell's response to that report? Basically, he said it was rubbish. Full quote:
"NPD's numbers on digital don't tend to have much reflection on reality. As much as I would love digital distribution to take over the world, I can't think of a single publisher (including ourselves) that sells even close to a majority of its units digitally. I am a big believer in the future of digital distribution but the numbers we typically hear from publishers is that it's about a third (which is pretty darn good, by the way)."
Source In other news, the Doctor Who games are finally available in the World outside Her Majesty's Great Britain and Northern Ireland, via [url=http://www.direct2drive.com/2/9642/product/Buy-Doctor-Who:-The-Adventure-Games---Episode-1-and-2-Download]Direct2Drive[/url] (and only Direct2Drive, apparently). First two episodes in a bundle for the massive price of five bucks.