I saw it. I've played Silent Hill 1 all the way through twice and I watched my brother and a friend play through 2 and 3. The movie follows Silent Hill 1 EXTREMELY closely for the first hour or so. I'm talking the camera angles are identicle, the plot is the same, the exact same music and locations, etc. It was really really cool. The movie looks just top notch. All of the locations are well put together and are JUST like Silent Hill in the games.
The bad part: the movie sucks. The acting is iffy, the dialogue from the script is just terrible, and the plot could have worked, but didn't. I enjoyed the first half of the movie because it was literally like playing through Silent Hill all the way up to the elementary school part (anyone remember the 2nd floor bathroom? Wait until you see the movie.
). After that it derailed from the first game and went on its own. That's when I started getting bored and didn't really enjoy it. Following the first game closely can keep my interest through the bad script, but after that stops, it all goes downhill.
If you've played the games, you should go see it just for the first half and how unbelievably they recreated the first game. If you haven't played the games, I can't really recommend it. I wasn't scared during the movie once and there were no startling parts. Hell, it wasn't even creepy. It was more like a "look how closely we can make the movie feel like the game" project instead of a horror movie.