Starbucks cafe car on a Swiss Federal Railways train
Starbucks press release, the Swiss Federal Railways press release and "Starbucks opens first train café in Switzerland," New York Daily News.
The NYDN story has some nice photos of the interior.
The café car is going through a nine-month test period.
It is definitely a method for enhancing food service on trains. A problem though for commuter railroad services is that many run at capacity so adding such a car might reduce the number of seats.