My friend saw this at the Toronto International Film Festival this year. Quentin Tarantino and Eli Roth were there for Q and A.
She said its probably one of the most graphic films she's ever seen. But a lot of stuff in the movie will most likely be cut out of a theatre release.
The movie is actually about a bunch of American tourists that get trapped in a hostel in Europe. They get lured there somehow and some sick business men or something actually get them in the hostels and torture them for their own kicks.
For example (spoilers I guess...well if you don't want to know any of the deaths don't look down)
One part has a girl with her eyeball hanging out of its socket and a guy has to cut her eyeball out. I really doubt that's going to stay in the theatre release.