How credible is the info on HondaPreview.com? I think the leather option is pure speculation on their part, since Honda has released no official word on the 2008 Civic.
The website also says there will be a diesel option in the MMC for the 2009 Civic? I dunno... I would think Honda is more likely to add a diesel option for the 2008 Accord (which isn't happening), since it's the flagship model and it's going through a FMC. Also, I would assume there would be other minor changes for the Civic's MMC (such as headlight/taillight housings) but they don't list anything of the sort.
Just thinking out loud: there may be a slight chance that they will bring the Euro 2.2L i-CTDi diesel engine into USDM Civics, but I feel it's highly improbable. It doesn't have more horsepower, just [lots] more torque and better gas mileage... and American consumers are not particularly enthusiastic about diesel in the first place. A leather, 140hp-diesel Civic EX with navigation will probably MSRP at $21k+, which infringes on Civic Si and Accord territory. The cost of retrofitting the assembly line to install diesel engines will probably outweigh the profit potential.
But if it happens, the Civic will come in five flavors: hybrid, natural gas, diesel, economy gasoline and performance gasoline engines. Pretty versatile! Anyone know if any other manufacturer does so many things with a single model? I'm just curious.