I just read that KB:AP also has native 3D mode:
http://www.rockpapershotgun.com/2009...ncess-arrives/
So I suppose this mode will be available with the physical boxed release of the game, perhaps even a exclusive-only feature of a 'Collector's Edition' due to the fact they have to supply the 3D glasses, (very much like 'Journey to the Center of the Earth, 3D version') But who knows, the Russian version if I recalled had them as well as a figurine and some other stuff, so I hope they also release one for the English speaking market.
But will the DL version be in 3D? Maybe not. Can someone from IC confirm this?