Is the diesel going to end up going the way of the dinosaur?

Just caught a little something on the radio today about England maybe limiting diesels in city limits because of increasing pollution.
With trains being diesel/electric hybrids and many big rigs going CNG I wouldnt say diesel going by the way side is a stretch.

I drive for UPS and many of the larger city Hubs are going to CNG for the big rigs. Ive heard they will be coming to Omaha eventually.

While I heard they lack the power of diesel they sure do burn clean.