rad idea.
if you limited yourself to live events/even delegation, that could take away some of the headache of screwing with existing js on the page. it'd be a tough one to do though. don't get me wrong.<p>hurdles i see are browser pagination (which would need to be done by iframe state storage/hash tags), favouritable urls (hash tags again), and inline js execution. you could also run into major memory issues if the previous page wasn't dumped properly, but all in all, a real cool idea, whether or not it's practical.