Looks like the economic feasability of a Diesel engine coming to North America are starting to waver. It was expected that by the time the next gen (2011, as a 2012 model) Ridgeline came about that so would a V6/V8 diesel engine. Now, rumours are that Honda is leaning towards a Hybrid model which of course would work with cylinder deactivation (VCM). There are still rumours of a 4.2 litre V8 engine, and it would make sense that Honda would have 2X options for this vehicle, 1X gas and 1X Hybrid or Diesel.
As always, I'll keep you posted as I hear anything else.