If the percentage difference price between 2.5L gas and higher output 2.2L diesel is the same as other markets, it'd be between $1700-1800 price premium... but that doesn't account for any market factors whatsoever.
I did a little more purely speculative napkin math just for fun... and it looks like the fuel cost break-even point for the AWD diesel over the AWD 2.5G in our market could easily be as much as 70-75k miles. That's assuming the 26mpg combined rated for the gas and an equivalent increase for the diesel (~33.75mpg), today's average prices of $3.563 for unleaded and $3.828 for diesel, and $1750 for the price difference. That's not considering any fuel price volatility, maintenance and depreciation cost differentials, real world mileage results, and the fact that we have no real freaking idea what it would cost if it even happens.
But then again, I personally want the diesel for the sheer fun factor of greater torque... the possibility of it being more cost effective over long-term ownership is just icing on the cake, especially because the torquier engine option for any other vehicle in the small crossover segment (like the turbo Kia Sportage or V6 Chevy Equinox) is a guaranteed increase in ownership cost both in terms of greater purchase price and poorer fuel economy.