Yep, especially on international flights. On my flights to EZE I regularly drink Pepsi Light from The Netherlands, Japan, China, and sometimes South America. On the 772 that has been running SEA-DEN-ORD I've found they almost always have the Chinese Pepsi Light.

I specifically ask for Pepsi Light if they have it. Usually if I ask them to keep an eye out for any for me they'll check around when they get a chance and bring me some later in the flight. ^