I watched Mirrors on Friday evening. My sister watched it on her birthday and said it was good and some of the girls from work have also watched it, one of which was getting nightmares about it weeks later.
Now I've sat through some spectacularly bad horror films in my time - the Unnamable^, Teeth^, etc - but Mirrors? Has to be right up there with the crappiest of the crap horror films.
Basically, it's about - well, mirrors. People see weird stuff in them and blah blah blah. Kiefer Sutherland comes along and starts to see the weird stuff and goes and talks to someone about it (his wife I think?) and it jumps from "I'm seeing weird shit in the mirrors" to "they're showing me another dimension". What? Where did you get that?
And. Mr Sutherland - who is normally a good actor - did such a bad acting job that even I, someone who skived off every single drama lesson and can't even keep a straight face when I'm trying to wind someone up, could have done a better job.
What a waste of time. I watched it Friday and I'm still annoyed that I wasted what could have been good, quality Farscape time. 
Not seen it but I've heard bad things about it. Don't think I will be seeing it either.