Apparently it's been out for awhile and I just hadn't paid attention, but the "Director's Cut" of Kate & Leopold is available on DVD and Blu-Ray.
You response to this news is likely, "Wait. What? Huh?" It's an understandable response, since you likely don't remember this Meg Ryan/Hugh Jackman time-travelling romcom in the first place, and even if you do, you would find it hard to believe that the world needed an alternate version. It was directed by unambitious studio-approved auteur wannabe James Mangold, whose movies can invariably be described as adequate.
But apparently he has enough pull to issue his own version of...a Meg Ryan romcom. I mean, look, I'm sorry, as these things go, Kate & Leopold is on the high end of the scale--based on the five minutes of it I saw on cable once--but let's not get carried away. This isn't Diego Rivera vs. Rockefeller. This isn't a masterpiece destroyed by philistines. This is a piece of studio product that its director inexplicably confused with art. We didn't need Mangold's, um, vision brought to us in full strength.
As compromised as they may be, I generally believe the released version of a movie should be the definitive version. Yeah, Walter Murch thought he was doing the world a favor by recutting Touch Of Evil to a version closer to Orson Welles' wishes...but however heavy-handed some of the studio-imposed aspects may be, it was that original version that critics have known and loved for years. And Francis Coppola can claim all he wants that the Apocalypse Now Redux cut is what he originally intended--though I'm pretty sure he's lying through his teeth--but it's not the movie he originally released, not the movie I saw and loved back in '79.
Sometimes a recut version isn't a bad idea--the studio really did butcher David Lean's original cut of Lawrence Of Arabia after the film had gone into release, so his altered version of it thirty years after the fact was an attempt to put back what was originally there--but generally speaking, I'm not a big fan of changing film history after the fact. Maybe the version we have isn't all that it could have been. But it's what we've got.