The rumor that has been going around about the whole R-12 ban issue is this.
Dupont holds the patent on the refrigerant R-12.  In the next couple of years
their patent will run out.  They also hold the patent for R-134a which will
not run out for many years to come.  You can draw your own conclusions from
this I would imagine.
I am not saying this is a fact, it is merely a rumor.  Of course I live about
an hour away from the Dupont facility in Delaware...
Its worth as much as you paid for it.
Ken Wilford
John 3:16