fwiw, i think sporkgoddess' points all are valid.
true, we don't know the specifics about why Girl was estranged from her Czech boyfriend, but the movie paints an unambiguously unflattering picture of him.
additionally, Guy wasn't completely over his old girlfriend, but i thought it was pretty clear there were only embers, not flames. (not that there's anything wrong with embers ...)
finally, while the ending would have been unbearably formulaic if Girl and Guy had gotten together, that doesn't negate the point about maintaining indie cred.
and as for the comment about getting back together for the sake of the child: how's the weather back there in 1956???
"You, sir, are a moron." (PlayItAgain)