It's not going to be good, so everyone should just forget about seeing what they think it should be. It will be a movie, and the name will be DOOM, and it will have The Rock in it - that's about where the decent shit is going to end and the perversion of the original idea will begin.
I have ragged on every game to film conversion in history and have been correct every time.. You will draw fans of the games, but the real fans will always never be totally pleased because they can't deliver what we want.. It just wouldn't be interesting to the audience as a whole.
The fact monsters will be in it, isn't exactly a saving grace.. We all saw what they did to some of the old monsters from the original games when they made DOOM 3... The one thing that would ever make me like this movie is to see a bonafied IMP - as well as some other original monsters.. Not some fucking Aliens knock-off, and not the BS remade models from DOOM3..
If you were to transplant the original DOOM monsters to film, the potential for them to be scary would be far greater than anything produced in DOOM 3 could ever hope to be.