The safety reason for the change is that bonding enclosures with a cuurent carrying conductor is not a good idea.
Regarding services...if this passes I plan on submitting the same concept for services in 2011. Of course, services don't typically fall under the scope of the NEC, but as written now, you don't have the option of installing an EGC from the transformer and bonding it to the enclosure, and floating the nuetral at the service.
