Like everyone else has had, highly entertaining. I was really enjoying all of the little comments concerning James' intelligence, but I like these best:
'Damn it. Why did he know this stuff? Of all the people to fawn over her it had to be someone with enough well-hidden brain power to spout off literary wonders at whim.'
AND
'He waved everything aside. Homework, responsibility, common sense… what on Earth was Dumbledore smoking?'

This thought just popped into my head: Obviously, this being a James/Lily story they're going to eventually get together. Have you thought about how that scene (or one after the relationship's confirmed) might shadow this whole Shakespeare back-and-forth that happens in the compartment? Just thoutht I'd toss that out. :)