There is the shorter European cut and the longer American cut most of us are familiar with. The American cut saw a video release in Europe only in the past few years. This caused confusion several years ago when the Eastman House announced a screening of the “longer version” and people jumped to the conclusion it had the hospital scene.

Someone badly misinterpreted the Italian text from the auction site and it’s spread like wildfire on the interwebs. It’s not a lost scene/version of the film. It’s more like stuff saved from the cutting room floor by Stanley’s personal assistant. And it’s just the one scene, AFAIK. I’ve compared it to the finished film, and it doesn’t seem like an alternate take either.
If anybody does have the hospital scene, do please speak up though. : )

It’s King’s book Doctor Sleep that’s being made, and it’s doubtful it’s going to be an actual sequel to the movie. A prequel to Kubrick’s film titled Overlook Hotel has been in development for a few years now, but there hasn’t been any news lately.
There is a major homage to The Shining in a movie hitting theaters very soon, but I won’t spoil it for anyone. 😉