The remake would be very loose and in fact the Hitchcock film (and the Patricia Highsmith novel on which it was based) are being treated as merely a jumping off point for a thriller about two teenagers who meet on a train, one of whom turns out to be a psychopath.
Part of the reason for so marked a departure from the notional source material seems to be the experience of the makers of Shia LaBeouf-starrer Disturbia, which was so clearly indebted to Hitchcock’s Rear Window. Although a judge recently ruled that Disturbia was sufficiently different from Rear Window to avoid losing a lawsuit issued by the estate of the author of the original story from which Hitchcock worked, this is clearly a case of once bitten, twice shy. Rather than go to the lengths of securing remake rights, the studios clearly prefer to make a looser adaptation and rely on the general familiarity of the story to grab the audience’s attention.
Perhaps what we will wind up with then, is something more akin to the spate of “home invasion” films of a few years ago (Unlawful Entry, Cape Fear, Ricochet, The Hand That Rocks The Cradle). “Before Sunrise” is also said to be an influence and although the “chance meeting” element can be said to be a common thread, I don’t recall Julie Delpy playing a raving lunatic.
The working title is currently “Teens on a Train” which is altogether quite hideous and will surely be ditched shortly. As this project develops, we’ll keep you posted.