Well, I mean, at the end of the day a train ride is a train ride. For HP fans, being able to ride "THE" Hogwarts Express will be exciting as is, but for the average person who doesn't give a rat's butt about HP or trains....
They could have the snack trolley, but other than that, I can't think of anything they could do to make a train ride more exciting. In the books nothing ever really happens, except in the third one, when Dementors board it.