I've heard thru a credible source that manufacturers of large diesel trucks will be tacking up to 10,000 dollars extra for 2007 emission requirement trucks for the fire service. If the fire service has to pay so much extra then I assume long haulers will be as well when they go to buy new trucks.
I don't really know what you're talking about.  Many trucking co's are middlemen and nothing more.  Most truckers are private contractors free to move to anther company for whatever the reason.  I run into issues with truckers damaged our equip but moved to another company and we can't charge people only companies.  So if they will be forced to take on $10K in charges, it will get passed on somehow.  Long haul trucking is dying if it's not dead already.  
I am not sure of the amount, but you are correct that there are additional costs associated with purchasing a new diesel vehicle.

The change consists of additional particulate traps, catalytic converters, etc... got a few friends that work in the heavy truck sector emmissions... it's all they talk about