A little history on DR. Pepper and who currently can sell Dr. Pepper...the jist of the story is that Pepsi, RC, Coke all have rights to distribute the product depending on what part of the country they are in(or world for that matter).
The Dr. Pepper FAQ
http://www.faqs.org/faqs/drink/dr-pepper/
"
"Dr Pepper is owned by Dr Pepper / Seven Up Inc a subsidiary of the
Cadbury PLC trading on the NYSE [as CSG -- Chris F.]. Dr Pepper is
distributed throughout the country by a variety of some very dedicated
bottlers who without them, the Dr Pepper brand would not be where it
is today. Coke, Pepsi, and RC bottlers sell Dr Pepper; it all depends
on who owns the franchise in a specific geographic area. The
breakdown is about 30% Coke, 40% Pepsi, 20% [other? He didn't say --
Chris F.] and some who just sell Dr Pepper......like our friends in
Dublin."
In December, 1998, Coca-Cola caused a stir by paying Cadbury-Schweppes
$1.85 billion for the right to distribute Cadbury-Schweppes sodas
(including Dr Pepper) in 120 countries, but the United States was not
one of them (neither were France or South Africa). So, in the U.S.,
Dr Pepper will still be distributed by whoever has the local franchise
rights, meaning that there will still be places where Coke doesn't own
the franchise and will continue to sell Mr. Pibb (and possibly another
brand--see question 10) to compete. And--just so no one gets
confused--Cadbury Schweppes still owns Dr Pepper. You'd be surprised
how quickly rumors get started from news like this."