The old spec was 0. 5% sulfur content in diesel fuel. This was reduced to 0. 05% sulfur content and "quote" the world was going to end and all injection pumps would suffer failure and premature wear. Lo and behold, very few injection pumps failed due to reduction of sulfur content. Several of older pumps had issues with the reduction in aromatics made at the same time as the reduction in sulfur content but these were rare and infrequent and resulted in some leaks but nothing that new o-rings did not solve.
In reality, the diesel fuel that you currently purchase in the US more than likely is already at 0. 01 to 0. 03% sulfur content as refineries gear up to meet the new 2007 pecs.
IMHO, don't worry / fret about what you can not change. As previously remarked upon, there are plenty of fuel additives that can be used if this is keeping you up at night.
Hopefully, this sheds some light on to the changes that have already occurred, indicating that the 2007 spec may not be a sweeping change as one might expect.