Novels (Austen) and plays (Shakespeare) that update well and (maybe) why

A note about why Austen novels "translate" so well into contemporary stories - not that I'm going to read Curtis Sittenfeld's Eligible, but has made me think, and remember the great film update of Emma, Clueless, that there seems to be something about comedies of manners, a la Austen, that carries over into a complete shift in time and setting. Is it that there are so many elements in a comedy of manners that are "universally acknowledged" - even w/ the change in setting, time, locale, they get at the essence of human behavior and personality, and though there are such vast political and social changes between 18th century England and 21st-centuary America, the heart of the matter doesn't alter that much after all. Austen's novels are great social documents of their time - almost too obvious; I remember meeting with a fellow grad student a thousand years ago who was English and scorned the very idea of his writing about politics in Austen because it was too easy, too obvious (he was, therefore, visiting the US and writing about Melville, which he considered strange, exotic, and challenging; I, conversely, was writing about politics in Shakespeare for similar reasons - wish I could remember his name) - but there's an element of Austen and of her genre that is willfully and deliberately free from the politics of her time. Obviously Shakespeare "updates" well, too! (and he was the great updater of his time), in particular to musicals: Kiss Me Kate, West Side Story, as well as film: The Rest Is Silence, He's the Man, Forbidden Planet (I actually haven't seen that), to name a few.